Boris Tsap - Academia.edu (original) (raw)
Papers by Boris Tsap
Organic Thin Films for Photonics Applications
Measurements of traveling wave modulators made from electrooptic polymer materials have now been ... more Measurements of traveling wave modulators made from electrooptic polymer materials have now been extended to over 110 GHz using high frequency commercial probes. An optical heterodyne detection system (figure 1) has been developed to characterize those devices at high frequencies. The use of both YAG and tunable semiconductor lasers (tunable range of 8 THz) has helped to improve the detection range and sensitivity of the system. The frequency response of the system was limited only by the operation of our coplanar connecting probes.
Microelectronic Structures and MEMS for Optical Processing II, 1996
ABSTRACT
Nonlinear Guided Waves and Their Applications, 2001
During the last, year polymer modulators have been used in a number of new applications. These ra... more During the last, year polymer modulators have been used in a number of new applications. These range from high speed optical A/D preprocessors to optically-controlled Phased Array Radars and high frequency, electro-optic millimeter wave oscillators.
Optical Technology for Microwave Applications VIII, 1997
ABSTRACT
Photonics for Space Environments IX, 2004
Empirical data regarding the radiation induced responses of Mach Zehnder interferometric electro-... more Empirical data regarding the radiation induced responses of Mach Zehnder interferometric electro-optic polymer based modulators (PBMs) operating at 1310 and 1 550 nm and broadband InP quantum dot (QD) polymer photodetectors (PPDs) operating into the near infrared (NIR) are reported. Modulators composed of spun-on materials and hybrid electostatically self assembled (ESA) and spun-on NLO materials are examined for changes to their half-wave voltage and insertion losses following a gamma-ray total dose of 163 krad(Si) and irradiation by 25.6 MeV protons at a fluence of-1O" cm2. Pre-and post-irradiation responses of ESA grown polymer detectors using InP QDs are examined for photovoltage degradation and aging effects. The data indicates an excellent potential for developing polymer based photonic (PBP) devices with increased radiation resistance suitable for transition to photonic space applications.
Solid-State Electronics, 1995
Abstract Cutoff frequency ft and corresponding power Pmft of a SiC microwave field-effect transis... more Abstract Cutoff frequency ft and corresponding power Pmft of a SiC microwave field-effect transistor (FET) are calculated using an analytical model that allows for nonlinear dependence of the carriers drift velocity on electric field. A simple analytical expression for the cutoff frequency is derived as a function of the basic FET parameters such as channel depth a, doping level N, gate length L, and material parameters: saturation drift velocity vs and carriers mobility μ. Conditions for the short and long channel devices are discussed. Comparison with the linear piece-wise approximation shows that for α-SiC FET with a = 0.15 μm, N = 1 × 1018 cm−3 at the drain voltage VD = Vp = 20 V, where Vp is a channel pinch-off voltage, field dependent mobility reduces the value of ft more than 1.5 times for the device with L in the range of 0.9–1.5 μm. This can partially explain the difference between previous theoretical calculations and experimental microwave performance of SiC FETs, and can lead to future optimization of SiC-based devices.
IEEE Photonics Technology Letters, 1999
Ultrahigh-speed integrated electrooptic polymer phase modulators have been fabricated and tested.... more Ultrahigh-speed integrated electrooptic polymer phase modulators have been fabricated and tested. They are made from a new nonlinear optical polymer, amino phenylene isophorone isoxazolone (APII), and are incorporated with integrated high-speed electrode transitions for W-band (75-110 GHz) operation. This new polymer has also been used to fabricate Mach-Zehnder modulators. These devices show good performance over a wide frequency band ranging to 40 GHz and have a V < 10 V. The measurements establish APII, and other chromophores specially designed to minimize chromophore-chromophore interaction, as strong contenders for fabricating modulators for commercial and military applications. Index Terms-Electrooptic modulation, finline transition, optical mixing, optical waveguides, traveling-wave devices. N ONLINEAR optical polymer materials have become a viable option for future high-performance integrated optics. This is especially true for high-frequency optical circuits because of their high nonlinearity, fast electronic response and near ideal velocity match for traveling-wave devices. Recent progress in research on nonlinear optical polymer materials and devices made from them confirm these predictions [1]-[4]. Previously, we demonstrated the operation of polymer traveling-wave phase modulators up to 110 GHz [5]. In those experiments, we used commercial coplanar waveguide probes (Picoprobe Model 120) to launch the driving power into the modulators. Though these probes provided excellent coupling of the power up to 120 GHz, they are unsuitable for integrated modulator structures due to their cost, size, and geometry. In this paper, we present the design and fabrication of a set of devices with monolithically integrated antipodal finline transitions, the structure of which is shown in Fig. 1. It has the advantage of low loss and high-dimensional fabrication tolerance. The transition gradually transforms the electric field
IEEE Photonics Technology Letters, 1998
Extension of a new optically controlled serially fed phased-array system to the receive mode of o... more Extension of a new optically controlled serially fed phased-array system to the receive mode of operation has been demonstrated. Our system uses the pulsed nature of microwave radars in a manner similar to clocked systems used in digital configurations. This novel approach requires only the use of one tunable laser, one optical modulator, and one chirped fiber grating unit. In this letter, we present an experimental demonstration of a two-element serially fed wide frequency range receiver that validates the feasibility of this novel concept. Our system can be readily expanded with multiple elements and transmit/receive modules for a complete phased array system.
IEEE Microwave and Guided Wave Letters, 1997
A new optically controlled phased-array system has been developed that has all the advantages of ... more A new optically controlled phased-array system has been developed that has all the advantages of true time delay (TTD), yet only requires one tunable laser, one optical modulator, and one fiber-optic grating unit. In this letter, a twoelement serial-feed transmitter has been assembled and tested to demonstrate the feasibility of this novel concept. Experimental results include TTD operation from 6-12 GHz using both 10and 1-ns pulses transmitted to five different directions.
IEEE Microwave and Guided Wave Letters, 1999
Integrated photonic radio frequency (RF) phase shifters with dc voltage control have been realize... more Integrated photonic radio frequency (RF) phase shifters with dc voltage control have been realized using a nested dual Mach-Zehnder modulator configuration in a new nonlinear optical polymer, CLD2-ISX. These modulators have a V V V of 10.8 V and exhibit excellent frequency performance measured up to 20 GHz. A near linear phase shift exceeding 108 was obtained for a 16-GHz microwave signal by tuning the dc control voltage over a 7.8-V range. It is expected that these integrated polymer phase shifters will find widespread applications in new types of lightweight optically controlled phased array systems.
Chemical Physics, 1999
Recent advances in polymer electro-optic polymers and in fabrication techniques have made possibl... more Recent advances in polymer electro-optic polymers and in fabrication techniques have made possible advances in polymer optical guided wave devices which bring them much closer to system ready. The processing of a new thermal set FTC polymer and its incorporation into a high-frequency, low-V optical amplitude modulator are reviewed. The design and p fabrication of 100 GHz modulators and their integration with rectangular metal waveguides using an anti-podal finline transition with a flexible Mylar substrate is discussed. High-speed polymer modulators with balanced outputs and the in situ trimming of the output coupler is described. More complex guided wave devices using polymers are demonstrated by the photonic rf phase shifter. Techniques for integrating both passive and active polymers into the same optical circuit without the need for mode matching is presented and demonstrated. To reduce the V of a polymer amplitude modulator to 1 V or p under, a technique of constant-bias voltage is demonstrated. Finally, a technique to directly laser write electro-optic polymer devices is reviewed.
Applied Physics Letters, 2005
Mach–Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyl... more Mach–Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyltetraene bridge-type chromophores within an amorphous polycarbonate host matrix were investigated for their resistance to gamma rays and 25.6 MeV protons. No device failures ...
Applied Physics Letters, 2000
Electro-optic polymer modulators operating at 1550 nm are demonstrated based on a nonlinear optic... more Electro-optic polymer modulators operating at 1550 nm are demonstrated based on a nonlinear optical polymer of a phenyltetraene bridged chromophore in polycarbonate. It has a large electro-optic coefficient at 1550 nm), good thermal stability (90° C), and low loss ( ...
Applied Physics Letters, 1997
ABSTRACT
Organic Thin Films for Photonics Applications
Measurements of traveling wave modulators made from electrooptic polymer materials have now been ... more Measurements of traveling wave modulators made from electrooptic polymer materials have now been extended to over 110 GHz using high frequency commercial probes. An optical heterodyne detection system (figure 1) has been developed to characterize those devices at high frequencies. The use of both YAG and tunable semiconductor lasers (tunable range of 8 THz) has helped to improve the detection range and sensitivity of the system. The frequency response of the system was limited only by the operation of our coplanar connecting probes.
Microelectronic Structures and MEMS for Optical Processing II, 1996
ABSTRACT
Nonlinear Guided Waves and Their Applications, 2001
During the last, year polymer modulators have been used in a number of new applications. These ra... more During the last, year polymer modulators have been used in a number of new applications. These range from high speed optical A/D preprocessors to optically-controlled Phased Array Radars and high frequency, electro-optic millimeter wave oscillators.
Optical Technology for Microwave Applications VIII, 1997
ABSTRACT
Photonics for Space Environments IX, 2004
Empirical data regarding the radiation induced responses of Mach Zehnder interferometric electro-... more Empirical data regarding the radiation induced responses of Mach Zehnder interferometric electro-optic polymer based modulators (PBMs) operating at 1310 and 1 550 nm and broadband InP quantum dot (QD) polymer photodetectors (PPDs) operating into the near infrared (NIR) are reported. Modulators composed of spun-on materials and hybrid electostatically self assembled (ESA) and spun-on NLO materials are examined for changes to their half-wave voltage and insertion losses following a gamma-ray total dose of 163 krad(Si) and irradiation by 25.6 MeV protons at a fluence of-1O" cm2. Pre-and post-irradiation responses of ESA grown polymer detectors using InP QDs are examined for photovoltage degradation and aging effects. The data indicates an excellent potential for developing polymer based photonic (PBP) devices with increased radiation resistance suitable for transition to photonic space applications.
Solid-State Electronics, 1995
Abstract Cutoff frequency ft and corresponding power Pmft of a SiC microwave field-effect transis... more Abstract Cutoff frequency ft and corresponding power Pmft of a SiC microwave field-effect transistor (FET) are calculated using an analytical model that allows for nonlinear dependence of the carriers drift velocity on electric field. A simple analytical expression for the cutoff frequency is derived as a function of the basic FET parameters such as channel depth a, doping level N, gate length L, and material parameters: saturation drift velocity vs and carriers mobility μ. Conditions for the short and long channel devices are discussed. Comparison with the linear piece-wise approximation shows that for α-SiC FET with a = 0.15 μm, N = 1 × 1018 cm−3 at the drain voltage VD = Vp = 20 V, where Vp is a channel pinch-off voltage, field dependent mobility reduces the value of ft more than 1.5 times for the device with L in the range of 0.9–1.5 μm. This can partially explain the difference between previous theoretical calculations and experimental microwave performance of SiC FETs, and can lead to future optimization of SiC-based devices.
IEEE Photonics Technology Letters, 1999
Ultrahigh-speed integrated electrooptic polymer phase modulators have been fabricated and tested.... more Ultrahigh-speed integrated electrooptic polymer phase modulators have been fabricated and tested. They are made from a new nonlinear optical polymer, amino phenylene isophorone isoxazolone (APII), and are incorporated with integrated high-speed electrode transitions for W-band (75-110 GHz) operation. This new polymer has also been used to fabricate Mach-Zehnder modulators. These devices show good performance over a wide frequency band ranging to 40 GHz and have a V < 10 V. The measurements establish APII, and other chromophores specially designed to minimize chromophore-chromophore interaction, as strong contenders for fabricating modulators for commercial and military applications. Index Terms-Electrooptic modulation, finline transition, optical mixing, optical waveguides, traveling-wave devices. N ONLINEAR optical polymer materials have become a viable option for future high-performance integrated optics. This is especially true for high-frequency optical circuits because of their high nonlinearity, fast electronic response and near ideal velocity match for traveling-wave devices. Recent progress in research on nonlinear optical polymer materials and devices made from them confirm these predictions [1]-[4]. Previously, we demonstrated the operation of polymer traveling-wave phase modulators up to 110 GHz [5]. In those experiments, we used commercial coplanar waveguide probes (Picoprobe Model 120) to launch the driving power into the modulators. Though these probes provided excellent coupling of the power up to 120 GHz, they are unsuitable for integrated modulator structures due to their cost, size, and geometry. In this paper, we present the design and fabrication of a set of devices with monolithically integrated antipodal finline transitions, the structure of which is shown in Fig. 1. It has the advantage of low loss and high-dimensional fabrication tolerance. The transition gradually transforms the electric field
IEEE Photonics Technology Letters, 1998
Extension of a new optically controlled serially fed phased-array system to the receive mode of o... more Extension of a new optically controlled serially fed phased-array system to the receive mode of operation has been demonstrated. Our system uses the pulsed nature of microwave radars in a manner similar to clocked systems used in digital configurations. This novel approach requires only the use of one tunable laser, one optical modulator, and one chirped fiber grating unit. In this letter, we present an experimental demonstration of a two-element serially fed wide frequency range receiver that validates the feasibility of this novel concept. Our system can be readily expanded with multiple elements and transmit/receive modules for a complete phased array system.
IEEE Microwave and Guided Wave Letters, 1997
A new optically controlled phased-array system has been developed that has all the advantages of ... more A new optically controlled phased-array system has been developed that has all the advantages of true time delay (TTD), yet only requires one tunable laser, one optical modulator, and one fiber-optic grating unit. In this letter, a twoelement serial-feed transmitter has been assembled and tested to demonstrate the feasibility of this novel concept. Experimental results include TTD operation from 6-12 GHz using both 10and 1-ns pulses transmitted to five different directions.
IEEE Microwave and Guided Wave Letters, 1999
Integrated photonic radio frequency (RF) phase shifters with dc voltage control have been realize... more Integrated photonic radio frequency (RF) phase shifters with dc voltage control have been realized using a nested dual Mach-Zehnder modulator configuration in a new nonlinear optical polymer, CLD2-ISX. These modulators have a V V V of 10.8 V and exhibit excellent frequency performance measured up to 20 GHz. A near linear phase shift exceeding 108 was obtained for a 16-GHz microwave signal by tuning the dc control voltage over a 7.8-V range. It is expected that these integrated polymer phase shifters will find widespread applications in new types of lightweight optically controlled phased array systems.
Chemical Physics, 1999
Recent advances in polymer electro-optic polymers and in fabrication techniques have made possibl... more Recent advances in polymer electro-optic polymers and in fabrication techniques have made possible advances in polymer optical guided wave devices which bring them much closer to system ready. The processing of a new thermal set FTC polymer and its incorporation into a high-frequency, low-V optical amplitude modulator are reviewed. The design and p fabrication of 100 GHz modulators and their integration with rectangular metal waveguides using an anti-podal finline transition with a flexible Mylar substrate is discussed. High-speed polymer modulators with balanced outputs and the in situ trimming of the output coupler is described. More complex guided wave devices using polymers are demonstrated by the photonic rf phase shifter. Techniques for integrating both passive and active polymers into the same optical circuit without the need for mode matching is presented and demonstrated. To reduce the V of a polymer amplitude modulator to 1 V or p under, a technique of constant-bias voltage is demonstrated. Finally, a technique to directly laser write electro-optic polymer devices is reviewed.
Applied Physics Letters, 2005
Mach–Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyl... more Mach–Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyltetraene bridge-type chromophores within an amorphous polycarbonate host matrix were investigated for their resistance to gamma rays and 25.6 MeV protons. No device failures ...
Applied Physics Letters, 2000
Electro-optic polymer modulators operating at 1550 nm are demonstrated based on a nonlinear optic... more Electro-optic polymer modulators operating at 1550 nm are demonstrated based on a nonlinear optical polymer of a phenyltetraene bridged chromophore in polycarbonate. It has a large electro-optic coefficient at 1550 nm), good thermal stability (90° C), and low loss ( ...
Applied Physics Letters, 1997
ABSTRACT