Guillermo Carpintero del Barrio | Universidad Carlos III de Madrid (original) (raw)

Papers by Guillermo Carpintero del Barrio

Research paper thumbnail of THz and Microwave Dual-Band Ultrafast Photoconductive Antenna

We present here experimental results for a new type of broadband emitter that covers two RF bands... more We present here experimental results for a new type of broadband emitter that covers two RF bands, one around 300 GHz and the other between 10 and 20 GHz. The higher band is excited by a square-spiral antenna driven at its center by a photoconductive switch. The lower band is excited by a dumbbell dipole antenna that is connected serially to the square spiral and also acts as the bias line for the switch. This type of dual-band performance should be beneficial for multiple system applications including free-space radar without atmospheric dropout, and biomedical reflective imaging.

Research paper thumbnail of Low noise performance of passively mode locked quantum-dash-based lasers under external optical feedback

Applied Physics Letters, 2009

We report on a systematic investigation of the effect of external optical feedback on 17 GHz pass... more We report on a systematic investigation of the effect of external optical feedback on 17 GHz passively mode-locked two-section lasers based on InAs/InP quantum dashes emitting at 1.58 μm. Narrowing of mode-beating linewidth down to a record value of ∼500 Hz is demonstrated over a large operating range.

Research paper thumbnail of Frequency Tuning of Symmetric Colliding Pulse Mode-Locked Laser through Asymmetric Biasing Intra-Cavity Phase Modulators

Proceeding and poster presented at: European Conference on Integrated Optics (ECIO). Eindhoven (N... more Proceeding and poster presented at: European Conference on Integrated Optics (ECIO). Eindhoven (Netherlands). 3-5 April, 2017In this paper we report a multimode interference reflector (MIR)-based linear cavity mode-locked laser (MLL) operating in the telecom C-band with a repetition rate of 30 GHz as shown in Fig. 1. A pair of intra-cavity electro-optic phase modulators (EOPM) enables spectral tuning of the optical and the photo-detected RF spectrum. As an asymmetric bias voltage increases up to 6 V, the RF frequency shift reaches 3 MHz. This photonic integrated circuit (PIC) was rapidly prototyped using generic photonic integration technology platform via industrial Multi-Project Wafer (MPW) runThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642355 FiWiN5

Research paper thumbnail of Réseau d’antennes à photo-mélange pour commutation photonique de faisceau en ondes millimétriques

Le Centre pour la Communication Scientifique Directe - HAL - memSIC, Jun 8, 2022

-Nous présentons un réseau d'antennes à excitation photonique et à commutation de faisceau pour d... more -Nous présentons un réseau d'antennes à excitation photonique et à commutation de faisceau pour des liaisons sans fil en bande E. Le réseau d'antennes se compose de deux sous-réseaux de patchs empilés servant de source primaire à une lentille en polytétrafluoroéthylène (PTFE) ; une photodiode alimente chaque sous-réseau. La lentille illuminée par l'un des sous-réseaux présente une directivité de 27 dBi, tout en permettant une commutation de faisceau entre ±2,7° avec un croisement de faisceau de-3 dB.

Research paper thumbnail of Tunable Mode-Locked Laser Photonic Integrated Circuit Using Intracavity Phase Modulators

Optical Fiber Communication Conference, 2017

Research paper thumbnail of Photoconductive THz Sources Driven at 1550 nm

Fundamentals of Terahertz Devices and Applications, 2021

Research paper thumbnail of Photonic-Enabled Beam Switching Mm-Wave Antenna Array

Journal of Lightwave Technology, 2021

We present a photonically-excited antenna array at E-band for scanning by beam switching in wirel... more We present a photonically-excited antenna array at E-band for scanning by beam switching in wireless links. First, we discuss the proposed technique applied to photonicenabled (sub)millimeter-wave transmitters. Next, we present our implementation; it consists of two sub-arrays of stacked patches as primary feeds of a Polytetrafluoroethylene (PTFE) lens, with one photodiode feeding each sub-array. To validate the assembly, the return loss and radiation patterns have been measured for one of the sub-arrays excited with a coplanar probe. In turn, the lens illuminated by one of the sub-arrays yields a directivity of 27 dBi. The radiation patterns measured for the transmitter module (including the lens) are in very good agreement with full-wave simulations, and they show that excitation of one of either sub-arrays allows beam switching between ±2.7 • with a beam crossover at −3 dB. Finally, we have tested the transmitter in a 0.6 m wireless link. Depending on the position of the detector and on which sub-array is excited, we have accomplished 5 Gbps transmission for on-off-keying modulation and direct detection (BER = 10 −11). The system constitutes an initial proof of photonic-assisted beam switching for mm-wave transmitters enabling broadband operation with a directive and switchable beam.

Research paper thumbnail of Circuitos Integrados Fotónicos para la Generación de Frecuencias Ópticas (OFCG)

MASKAY, 2018

Se presentan los avances realizados en el desarrollo de generadores de peines de frecuencias ópti... more Se presentan los avances realizados en el desarrollo de generadores de peines de frecuencias ópticas (OFCG, Optical Frequency Comb Generator) mediante circuitos integrados fotónicos (PIC, Photonic Integrated Circuits). Estos son diseñados y fabricados en un proceso de oblea multi-proyecto de una plataforma genérica de integración. Se muestran los resultados experimentales de las diferentes clases de OFCG destacando los anchos de banda logrados, en el orden de THz. Se resalta la factibilidad de disponer circuitos fotónicos miniaturizados en sistemas de banda ancha y otras aplicaciones futuras en el marco de la nanotecnología.

Research paper thumbnail of InP femtosecond mode-locked laser in a compound feedback cavity with a switchable repetition rate

Optics letters, 2018

A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity... more A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity is composed of a colliding pulse mode-locking (ML) subcavity and a passive Fabry-Perot feedback subcavity. These two 1.6 mm long subcavities are coupled by using on-chip reflectors at both ends, enabling harmonic mode locking. By changing DC-bias conditions, optical mode spacing from 50 to 450 GHz is experimentally demonstrated. Ultrafast pulses shorter than 0.3 ps emitted from this laser diode are shown in autocorrelation traces.

Research paper thumbnail of Femtosecond pulse and terahertz two-tone generation from facet-free multi-segment laser diode in InP-based generic foundry platform

Optics express, Jan 9, 2018

In this paper, a monolithically integrated ∼1.55 µm semiconductor laser in the fourth harmonic co... more In this paper, a monolithically integrated ∼1.55 µm semiconductor laser in the fourth harmonic colliding pulse mode locking configuration is reported. This device was developed within a multi-project wafer run at an InP-based active-passive generic foundry. The 1.66-mm Fabry-Pérot cavity is formed with two on-chip reflector building blocks rather than cleaved facets. In the cavity, three absorber sections symmetrically divide the cavity in four gain segments. This laser diode is able to emit 100-GHz pulse trains with 500-fs pulse duration as well as two-tone emissions with a frequency separation of 2.7 THz. The dependence of the spectral behavior on the forward bias current for gain sections and the reverse bias voltage for absorber sections are experimentally demonstrated.

Research paper thumbnail of 18-THz-wide optical frequency comb emitted from monolithic passively mode-locked semiconductor quantum-well laser

Optics Letters, 2017

We report on an optical frequency comb with 14nm (∼1.8 THz) spectral bandwidth at-3 dB level that... more We report on an optical frequency comb with 14nm (∼1.8 THz) spectral bandwidth at-3 dB level that is generated using a passively mode-locked quantum-well (QW) laser in photonic integrated circuits (PICs) fabricated through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse modelocked laser cavity is defined by on-chip reflectors incorporating intracavity phase modulators followed by an extra-cavity SOA as booster amplifier. A 1.8-THz-wide optical comb spectrum is presented with ultrafast pulse that is 0.35-ps-wide. The radio frequency beat note has a 3-dB linewidth of 450 kHz and 35-dB SNR.

Research paper thumbnail of Optical frequency comb generator based on a monolithically integrated passive mode-locked ring laser with a Mach–Zehnder interferometer

Optics Letters, 2016

We report the demonstration of an optical-frequency comb generator based on a monolithically inte... more We report the demonstration of an optical-frequency comb generator based on a monolithically integrated ring laser fabricated in a multiproject wafer run in an active/passive integration process in a generic foundry using standardized building blocks. The device is based on a passive modelocked ring laser architecture, which includes a Mach-Zehnder interferometer to flatten the spectral shape of the comb output. This structure allows monolithic integration with other optical components, such as optical filters for wavelength selection, or dual wavelength lasers for their stabilization. The results show a −10 dB span of the optical comb of 8.7 nm (1.08 THz), with comb spacing of 10.16 GHz. We also obtain a flatness of 44 lines within a 1.8 dB power variation.

Research paper thumbnail of Mode-locked laser with pulse interleavers in a monolithic photonic integrated circuit for millimeter wave and terahertz carrier generation

Optics letters, Jan 15, 2017

This Letter presents a photonics-based millimeter wave and terahertz frequency synthesizer using ... more This Letter presents a photonics-based millimeter wave and terahertz frequency synthesizer using a monolithic InP photonic integrated circuit composed of a mode-locked laser (MLL) and two pulse interleaver stages to multiply the repetition rate frequency. The MLL is a multiple colliding pulse MLL producing an 80 GHz repetition rate pulse train. Through two consecutive monolithic pulse interleaver structures, each doubling the repetition rate, we demonstrate the achievement of 160 and 320 GHz. The fabrication was done on a multi-project wafer run of a generic InP photonic technology platform.

Research paper thumbnail of Mode-locked photonic integrated circuits for millimeter and terahertz wave wireless communications

2016 Progress in Electromagnetic Research Symposium (PIERS), 2016

We present a 160 GHz pulsed source, based on an on-chip repetition rate multiplier scheme to doub... more We present a 160 GHz pulsed source, based on an on-chip repetition rate multiplier scheme to double the repetition rate of an 80 GHz multiple pulse colliding mode-locked (mCPM) laser. For the first time to our knowledge, we demonstrate the monolithic integration of the mCPM laser and the pulse rate multiplier structures, using a generic foundry approach. From a 20 GHz fundamental repetition rate we achieve a x4 increase, up to 160 GHz. The FWHM pulsewidth of 160 GHz pulse train is 2.77 ps.

Research paper thumbnail of Characterization of an InGaAs/InP-based Echelle mirror multiplexer for widely-tunable mid-IR sources based on quantum cascade lasers

Novel In-Plane Semiconductor Lasers XIV, 2015

We present the experimental characterization results of a 15-to-1 wavelength multiplexer for a Di... more We present the experimental characterization results of a 15-to-1 wavelength multiplexer for a Distributed Feedback Quantum Cascade Laser (DFB QCL) array operating in the 7-8.5 μm (mid-long) infrared (IR) range. This design is customized for its use to combine the output from a DFB QCL array with a 0.1 μm wavelength channel spacing for spectroscopy applications, and it is proposed in order to achieve a continuous tuning range overcoming the limited tunability of a single QCLs, required for multi-gas or complex molecule detection. This multiplexer is based on an Echelle diffraction mirror grating scheme, in which multiple output waveguides are deliberately implemented in the design to de-risk for wavelength deviations in the fabrication process. We optimized the location of the input and output guides in order to allow for monolithic integration of the DFB QCL arrays, which would provide for a number of advantages such as a higher stability, less complexity and lower cost over other technologies such as external cavities. We discuss the effects over the device performance of the design, such as the diffraction effects, input channel width overlapping/crosstalk and input channel profile, which are very important to address in order to avoid unaccounted transmission losses. Other parameters such as the profile of the input and output waveguides and fabrication limitations are also discussed as their effect on the device is observed. A series of characterization tests are presented in order to compare the simulation results to the experimental data, which suggests that these multiplexers are a suitable option compared to other IR multiplexer schemes in terms of size and power transmission.

Research paper thumbnail of Experimental evidence of coupling effects in a twin-ridge laser

Optics Letters, 2009

We present for the first time (to our knowledge) experimental data on the intrinsic relaxation os... more We present for the first time (to our knowledge) experimental data on the intrinsic relaxation oscillation frequency in a twin-ridge laser array. We present a detailed analysis of the frequency response of the device, both under single-ridge operation as well as in twin ridge. We demonstrate the strong influence that the injection current on one ridge has over the relaxation oscillation frequency of the other. Using previously defined dependencies for the twin ridge, we link the imaginary part of the coupling constant to the observed variations in the relaxation oscillation frequency, proposing a procedure to determine a parameter that so far has been used as a free adjustment value.

Research paper thumbnail of High-speed photodiodes for InP-based photonic integrated circuits

Optics Express, 2012

We demonstrate the feasibility of monolithic integration of evanescently coupled Uni-Traveling Ca... more We demonstrate the feasibility of monolithic integration of evanescently coupled Uni-Traveling Carrier Photodiodes (UTC-PDs) having a bandwidth exceeding 100 GHz with Multimode Interference (MMI) couplers. This platform is suitable for active-passive, butt-joint monolithic integration with various Multiple Quantum Well (MQW) devices for narrow linewidth millimeter-wave photomixing sources. The fabricated devices achieved a high 3-dB bandwidth of up to 110 GHz and a generated output power of more than 0 dBm (1 mW) at 120 GHz with a flat frequency response over the microwave F-band (90-140 GHz).

Research paper thumbnail of Observation of phase noise reduction in photonically synthesized sub-THz signals using a passively mode-locked laser diode and highly selective optical filtering

Optics Express, 2012

 Users may download and print one copy of any publication from the public portal for the purpose... more  Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Research paper thumbnail of Microwave Photonic Integrated Circuits for Millimeter-Wave Wireless Communications

Journal of Lightwave Technology, 2014

This paper describes the advantages that the introduction of photonic integration technologies ca... more This paper describes the advantages that the introduction of photonic integration technologies can bring to the development of photonic-enabled wireless communications systems operating in the millimeter wave frequency range. We present two approaches for the development of dual wavelength sources for heterodyne-based millimeter wave generation realized using active/passive photonic integration technology. One approach integrates monolithically two distributed feedback semiconductor lasers along with semiconductor optical amplifiers, wavelength combiners, electro-optic modulators and broad bandwidth photodiodes. The other uses a generic photonic integration platform, developing narrow linewidth dual wavelength lasers based on arrayed waveguide gratings. Moreover, data transmission over a wireless link at a carrier wave frequency above 100 GHz is presented, in which the two lasers are free-running, and the modulation is directly applied to the single photonic chip without the requirement of any additional component.

Research paper thumbnail of Comparison of Monolithic Optical Frequency Comb Generators Based on Passively Mode-Locked Lasers for Continuous Wave mm-Wave and Sub-THz Generation

Journal of Lightwave Technology, 2012

In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry-Perot c... more In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry-Perot cavity and a ring cavity laser are characterized and evaluated as monolithic Optical Frequency Comb Generators (OFCG) for CW sub-THz generation. An extensive characterization of the devices under study is carried out based on an automated measurement system that systematically evaluates the dynamic characteristics of the devices, focusing on the figures of merit that define the optimum performance of a pulsed laser source when considered as an OFCG. Sub-THz signals generated with both devices at 60 GHz and 90 GHz are presented and analyzed in terms of electrical linewidth to compare such components for mm-Wave and sub-THz photonic generation. This work offers a systematic comparison of PMLLD devices for OFCG operation and provides reference information of the performance of two different device topologies that can be used for the implementation of photonic integrated sub-THz CW generation. Index Terms-mm-wave and THz photonic synthesis, optical filtering, Optical Frequency Comb, optical heterodyne photomixing, passively mode-locked lasers. I. INTRODUCTION URING the last decade, there has been a great research effort centered in the development of suitable generation and detection technologies to satisfy the needs of the frequency region known as the "THz gap" [1, 2]. This is mainly because of the great number of potential applications identified in this region, namely, imaging for security [3, 4] or biomedicine [5], spectroscopy [6] or short-range high data rate communications [7], among others. For some of them, even Manuscript received May 4, 2012.

Research paper thumbnail of THz and Microwave Dual-Band Ultrafast Photoconductive Antenna

We present here experimental results for a new type of broadband emitter that covers two RF bands... more We present here experimental results for a new type of broadband emitter that covers two RF bands, one around 300 GHz and the other between 10 and 20 GHz. The higher band is excited by a square-spiral antenna driven at its center by a photoconductive switch. The lower band is excited by a dumbbell dipole antenna that is connected serially to the square spiral and also acts as the bias line for the switch. This type of dual-band performance should be beneficial for multiple system applications including free-space radar without atmospheric dropout, and biomedical reflective imaging.

Research paper thumbnail of Low noise performance of passively mode locked quantum-dash-based lasers under external optical feedback

Applied Physics Letters, 2009

We report on a systematic investigation of the effect of external optical feedback on 17 GHz pass... more We report on a systematic investigation of the effect of external optical feedback on 17 GHz passively mode-locked two-section lasers based on InAs/InP quantum dashes emitting at 1.58 μm. Narrowing of mode-beating linewidth down to a record value of ∼500 Hz is demonstrated over a large operating range.

Research paper thumbnail of Frequency Tuning of Symmetric Colliding Pulse Mode-Locked Laser through Asymmetric Biasing Intra-Cavity Phase Modulators

Proceeding and poster presented at: European Conference on Integrated Optics (ECIO). Eindhoven (N... more Proceeding and poster presented at: European Conference on Integrated Optics (ECIO). Eindhoven (Netherlands). 3-5 April, 2017In this paper we report a multimode interference reflector (MIR)-based linear cavity mode-locked laser (MLL) operating in the telecom C-band with a repetition rate of 30 GHz as shown in Fig. 1. A pair of intra-cavity electro-optic phase modulators (EOPM) enables spectral tuning of the optical and the photo-detected RF spectrum. As an asymmetric bias voltage increases up to 6 V, the RF frequency shift reaches 3 MHz. This photonic integrated circuit (PIC) was rapidly prototyped using generic photonic integration technology platform via industrial Multi-Project Wafer (MPW) runThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642355 FiWiN5

Research paper thumbnail of Réseau d’antennes à photo-mélange pour commutation photonique de faisceau en ondes millimétriques

Le Centre pour la Communication Scientifique Directe - HAL - memSIC, Jun 8, 2022

-Nous présentons un réseau d'antennes à excitation photonique et à commutation de faisceau pour d... more -Nous présentons un réseau d'antennes à excitation photonique et à commutation de faisceau pour des liaisons sans fil en bande E. Le réseau d'antennes se compose de deux sous-réseaux de patchs empilés servant de source primaire à une lentille en polytétrafluoroéthylène (PTFE) ; une photodiode alimente chaque sous-réseau. La lentille illuminée par l'un des sous-réseaux présente une directivité de 27 dBi, tout en permettant une commutation de faisceau entre ±2,7° avec un croisement de faisceau de-3 dB.

Research paper thumbnail of Tunable Mode-Locked Laser Photonic Integrated Circuit Using Intracavity Phase Modulators

Optical Fiber Communication Conference, 2017

Research paper thumbnail of Photoconductive THz Sources Driven at 1550 nm

Fundamentals of Terahertz Devices and Applications, 2021

Research paper thumbnail of Photonic-Enabled Beam Switching Mm-Wave Antenna Array

Journal of Lightwave Technology, 2021

We present a photonically-excited antenna array at E-band for scanning by beam switching in wirel... more We present a photonically-excited antenna array at E-band for scanning by beam switching in wireless links. First, we discuss the proposed technique applied to photonicenabled (sub)millimeter-wave transmitters. Next, we present our implementation; it consists of two sub-arrays of stacked patches as primary feeds of a Polytetrafluoroethylene (PTFE) lens, with one photodiode feeding each sub-array. To validate the assembly, the return loss and radiation patterns have been measured for one of the sub-arrays excited with a coplanar probe. In turn, the lens illuminated by one of the sub-arrays yields a directivity of 27 dBi. The radiation patterns measured for the transmitter module (including the lens) are in very good agreement with full-wave simulations, and they show that excitation of one of either sub-arrays allows beam switching between ±2.7 • with a beam crossover at −3 dB. Finally, we have tested the transmitter in a 0.6 m wireless link. Depending on the position of the detector and on which sub-array is excited, we have accomplished 5 Gbps transmission for on-off-keying modulation and direct detection (BER = 10 −11). The system constitutes an initial proof of photonic-assisted beam switching for mm-wave transmitters enabling broadband operation with a directive and switchable beam.

Research paper thumbnail of Circuitos Integrados Fotónicos para la Generación de Frecuencias Ópticas (OFCG)

MASKAY, 2018

Se presentan los avances realizados en el desarrollo de generadores de peines de frecuencias ópti... more Se presentan los avances realizados en el desarrollo de generadores de peines de frecuencias ópticas (OFCG, Optical Frequency Comb Generator) mediante circuitos integrados fotónicos (PIC, Photonic Integrated Circuits). Estos son diseñados y fabricados en un proceso de oblea multi-proyecto de una plataforma genérica de integración. Se muestran los resultados experimentales de las diferentes clases de OFCG destacando los anchos de banda logrados, en el orden de THz. Se resalta la factibilidad de disponer circuitos fotónicos miniaturizados en sistemas de banda ancha y otras aplicaciones futuras en el marco de la nanotecnología.

Research paper thumbnail of InP femtosecond mode-locked laser in a compound feedback cavity with a switchable repetition rate

Optics letters, 2018

A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity... more A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity is composed of a colliding pulse mode-locking (ML) subcavity and a passive Fabry-Perot feedback subcavity. These two 1.6 mm long subcavities are coupled by using on-chip reflectors at both ends, enabling harmonic mode locking. By changing DC-bias conditions, optical mode spacing from 50 to 450 GHz is experimentally demonstrated. Ultrafast pulses shorter than 0.3 ps emitted from this laser diode are shown in autocorrelation traces.

Research paper thumbnail of Femtosecond pulse and terahertz two-tone generation from facet-free multi-segment laser diode in InP-based generic foundry platform

Optics express, Jan 9, 2018

In this paper, a monolithically integrated ∼1.55 µm semiconductor laser in the fourth harmonic co... more In this paper, a monolithically integrated ∼1.55 µm semiconductor laser in the fourth harmonic colliding pulse mode locking configuration is reported. This device was developed within a multi-project wafer run at an InP-based active-passive generic foundry. The 1.66-mm Fabry-Pérot cavity is formed with two on-chip reflector building blocks rather than cleaved facets. In the cavity, three absorber sections symmetrically divide the cavity in four gain segments. This laser diode is able to emit 100-GHz pulse trains with 500-fs pulse duration as well as two-tone emissions with a frequency separation of 2.7 THz. The dependence of the spectral behavior on the forward bias current for gain sections and the reverse bias voltage for absorber sections are experimentally demonstrated.

Research paper thumbnail of 18-THz-wide optical frequency comb emitted from monolithic passively mode-locked semiconductor quantum-well laser

Optics Letters, 2017

We report on an optical frequency comb with 14nm (∼1.8 THz) spectral bandwidth at-3 dB level that... more We report on an optical frequency comb with 14nm (∼1.8 THz) spectral bandwidth at-3 dB level that is generated using a passively mode-locked quantum-well (QW) laser in photonic integrated circuits (PICs) fabricated through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse modelocked laser cavity is defined by on-chip reflectors incorporating intracavity phase modulators followed by an extra-cavity SOA as booster amplifier. A 1.8-THz-wide optical comb spectrum is presented with ultrafast pulse that is 0.35-ps-wide. The radio frequency beat note has a 3-dB linewidth of 450 kHz and 35-dB SNR.

Research paper thumbnail of Optical frequency comb generator based on a monolithically integrated passive mode-locked ring laser with a Mach–Zehnder interferometer

Optics Letters, 2016

We report the demonstration of an optical-frequency comb generator based on a monolithically inte... more We report the demonstration of an optical-frequency comb generator based on a monolithically integrated ring laser fabricated in a multiproject wafer run in an active/passive integration process in a generic foundry using standardized building blocks. The device is based on a passive modelocked ring laser architecture, which includes a Mach-Zehnder interferometer to flatten the spectral shape of the comb output. This structure allows monolithic integration with other optical components, such as optical filters for wavelength selection, or dual wavelength lasers for their stabilization. The results show a −10 dB span of the optical comb of 8.7 nm (1.08 THz), with comb spacing of 10.16 GHz. We also obtain a flatness of 44 lines within a 1.8 dB power variation.

Research paper thumbnail of Mode-locked laser with pulse interleavers in a monolithic photonic integrated circuit for millimeter wave and terahertz carrier generation

Optics letters, Jan 15, 2017

This Letter presents a photonics-based millimeter wave and terahertz frequency synthesizer using ... more This Letter presents a photonics-based millimeter wave and terahertz frequency synthesizer using a monolithic InP photonic integrated circuit composed of a mode-locked laser (MLL) and two pulse interleaver stages to multiply the repetition rate frequency. The MLL is a multiple colliding pulse MLL producing an 80 GHz repetition rate pulse train. Through two consecutive monolithic pulse interleaver structures, each doubling the repetition rate, we demonstrate the achievement of 160 and 320 GHz. The fabrication was done on a multi-project wafer run of a generic InP photonic technology platform.

Research paper thumbnail of Mode-locked photonic integrated circuits for millimeter and terahertz wave wireless communications

2016 Progress in Electromagnetic Research Symposium (PIERS), 2016

We present a 160 GHz pulsed source, based on an on-chip repetition rate multiplier scheme to doub... more We present a 160 GHz pulsed source, based on an on-chip repetition rate multiplier scheme to double the repetition rate of an 80 GHz multiple pulse colliding mode-locked (mCPM) laser. For the first time to our knowledge, we demonstrate the monolithic integration of the mCPM laser and the pulse rate multiplier structures, using a generic foundry approach. From a 20 GHz fundamental repetition rate we achieve a x4 increase, up to 160 GHz. The FWHM pulsewidth of 160 GHz pulse train is 2.77 ps.

Research paper thumbnail of Characterization of an InGaAs/InP-based Echelle mirror multiplexer for widely-tunable mid-IR sources based on quantum cascade lasers

Novel In-Plane Semiconductor Lasers XIV, 2015

We present the experimental characterization results of a 15-to-1 wavelength multiplexer for a Di... more We present the experimental characterization results of a 15-to-1 wavelength multiplexer for a Distributed Feedback Quantum Cascade Laser (DFB QCL) array operating in the 7-8.5 μm (mid-long) infrared (IR) range. This design is customized for its use to combine the output from a DFB QCL array with a 0.1 μm wavelength channel spacing for spectroscopy applications, and it is proposed in order to achieve a continuous tuning range overcoming the limited tunability of a single QCLs, required for multi-gas or complex molecule detection. This multiplexer is based on an Echelle diffraction mirror grating scheme, in which multiple output waveguides are deliberately implemented in the design to de-risk for wavelength deviations in the fabrication process. We optimized the location of the input and output guides in order to allow for monolithic integration of the DFB QCL arrays, which would provide for a number of advantages such as a higher stability, less complexity and lower cost over other technologies such as external cavities. We discuss the effects over the device performance of the design, such as the diffraction effects, input channel width overlapping/crosstalk and input channel profile, which are very important to address in order to avoid unaccounted transmission losses. Other parameters such as the profile of the input and output waveguides and fabrication limitations are also discussed as their effect on the device is observed. A series of characterization tests are presented in order to compare the simulation results to the experimental data, which suggests that these multiplexers are a suitable option compared to other IR multiplexer schemes in terms of size and power transmission.

Research paper thumbnail of Experimental evidence of coupling effects in a twin-ridge laser

Optics Letters, 2009

We present for the first time (to our knowledge) experimental data on the intrinsic relaxation os... more We present for the first time (to our knowledge) experimental data on the intrinsic relaxation oscillation frequency in a twin-ridge laser array. We present a detailed analysis of the frequency response of the device, both under single-ridge operation as well as in twin ridge. We demonstrate the strong influence that the injection current on one ridge has over the relaxation oscillation frequency of the other. Using previously defined dependencies for the twin ridge, we link the imaginary part of the coupling constant to the observed variations in the relaxation oscillation frequency, proposing a procedure to determine a parameter that so far has been used as a free adjustment value.

Research paper thumbnail of High-speed photodiodes for InP-based photonic integrated circuits

Optics Express, 2012

We demonstrate the feasibility of monolithic integration of evanescently coupled Uni-Traveling Ca... more We demonstrate the feasibility of monolithic integration of evanescently coupled Uni-Traveling Carrier Photodiodes (UTC-PDs) having a bandwidth exceeding 100 GHz with Multimode Interference (MMI) couplers. This platform is suitable for active-passive, butt-joint monolithic integration with various Multiple Quantum Well (MQW) devices for narrow linewidth millimeter-wave photomixing sources. The fabricated devices achieved a high 3-dB bandwidth of up to 110 GHz and a generated output power of more than 0 dBm (1 mW) at 120 GHz with a flat frequency response over the microwave F-band (90-140 GHz).

Research paper thumbnail of Observation of phase noise reduction in photonically synthesized sub-THz signals using a passively mode-locked laser diode and highly selective optical filtering

Optics Express, 2012

 Users may download and print one copy of any publication from the public portal for the purpose... more  Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Research paper thumbnail of Microwave Photonic Integrated Circuits for Millimeter-Wave Wireless Communications

Journal of Lightwave Technology, 2014

This paper describes the advantages that the introduction of photonic integration technologies ca... more This paper describes the advantages that the introduction of photonic integration technologies can bring to the development of photonic-enabled wireless communications systems operating in the millimeter wave frequency range. We present two approaches for the development of dual wavelength sources for heterodyne-based millimeter wave generation realized using active/passive photonic integration technology. One approach integrates monolithically two distributed feedback semiconductor lasers along with semiconductor optical amplifiers, wavelength combiners, electro-optic modulators and broad bandwidth photodiodes. The other uses a generic photonic integration platform, developing narrow linewidth dual wavelength lasers based on arrayed waveguide gratings. Moreover, data transmission over a wireless link at a carrier wave frequency above 100 GHz is presented, in which the two lasers are free-running, and the modulation is directly applied to the single photonic chip without the requirement of any additional component.

Research paper thumbnail of Comparison of Monolithic Optical Frequency Comb Generators Based on Passively Mode-Locked Lasers for Continuous Wave mm-Wave and Sub-THz Generation

Journal of Lightwave Technology, 2012

In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry-Perot c... more In this paper, two different Passive Mode-Locked Laser Diodes (PMLLD) structures, a Fabry-Perot cavity and a ring cavity laser are characterized and evaluated as monolithic Optical Frequency Comb Generators (OFCG) for CW sub-THz generation. An extensive characterization of the devices under study is carried out based on an automated measurement system that systematically evaluates the dynamic characteristics of the devices, focusing on the figures of merit that define the optimum performance of a pulsed laser source when considered as an OFCG. Sub-THz signals generated with both devices at 60 GHz and 90 GHz are presented and analyzed in terms of electrical linewidth to compare such components for mm-Wave and sub-THz photonic generation. This work offers a systematic comparison of PMLLD devices for OFCG operation and provides reference information of the performance of two different device topologies that can be used for the implementation of photonic integrated sub-THz CW generation. Index Terms-mm-wave and THz photonic synthesis, optical filtering, Optical Frequency Comb, optical heterodyne photomixing, passively mode-locked lasers. I. INTRODUCTION URING the last decade, there has been a great research effort centered in the development of suitable generation and detection technologies to satisfy the needs of the frequency region known as the "THz gap" [1, 2]. This is mainly because of the great number of potential applications identified in this region, namely, imaging for security [3, 4] or biomedicine [5], spectroscopy [6] or short-range high data rate communications [7], among others. For some of them, even Manuscript received May 4, 2012.