Full Spectrum Millimeter-Wave Modulation in Thin-Film LiNbO3 (original) (raw)
Related papers
Thin Film Lithium Niobate Electro-Optic Modulator for 1064 nm Wavelength
IEEE Photonics Technology Letters, 2021
We present a thin film crystal ion sliced (CIS) LiNbO 3 phase modulator that demonstrates an unprecedented measured electro-optic (EO) response up to 500 GHz. Shallow rib waveguides are utilized for guiding a single transverse electric (TE) optical mode, and Au coplanar waveguides (CPWs) support the modulating radio frequency (RF) mode. Precise index matching between the co-propagating RF and optical modes is responsible for the device's broadband response, which is estimated to extend even beyond 500 GHz. Matching the velocities of these co-propagating RF and optical modes is realized by cladding the modulator's interaction region in a thin UV15 polymer layer, which increases the RF modal index. The fabricated modulator possesses a tightly confined optical mode, which lends itself to a strong interaction between the modulating RF field and the guided optical carrier; resulting in a measured DC half-wave voltage of 3.8 V•cm −1. The design, fabrication, and characterization of our broadband modulator is presented in this work.
Microwave and Optical Technology Letters, 2009
In this article, a transition of coplanar line to substrateintegrated waveguide onto electro-optical LiNbO 3 substrate for the design of traveling-wave optical phase modulator at 60 GHz were proposed, designed, and fabricated for the first time. Micromachining of the LiNbO 3 substrate, which is transparent to a wide range of laser wavelengths, was done by using Excimer laser. Metallized via holes around the coplanar line are considered for the purpose of mode suppression. Also, a cavity resonator was designed to increase the circuit bandwidth. Measurement results show about 5 GHz bandwidth for the demonstrated substrate-integrated electro-optical waveguide.
Waveguide electro-optic modulation in micro-engineered LiNbO 3
Journal of Optics A: Pure and Applied Optics, 2008
In this paper, after describing the basics of LiNbO 3 based integrated electro-optic modulators, we will show how techniques such as etching, domain inversion and thin film processing can be used to realize new geometries which can take the performance to unprecedented levels. In particular we will review recent results on the use of domain inversion on a micron scale to improve the electro-optic response of LiNbO 3 waveguide modulators in terms of bandwidth and driving voltage. These applications of domain inversion techniques might be even more important and commercially valuable than those in nonlinear optics (e.g. quasi-phase-matched optical parametric devices). With respect to standard single-domain structures, larger bandwidths and lower driving voltages can be obtained, thus achieving figure of merits for the electro-optic response that are up to 50% larger. As a demonstration, a chirp-free modulator, having ∼2 V switching voltage and bandwidth of 15 GHz, was fabricated by placing the waveguide arms of a Mach-Zehnder interferometer in opposite domain oriented regions. The modulator, as indicated by system measurements, could be driven in a single-drive configuration with inexpensive low-voltage drivers, e.g. SiGe based, typically used for electro-absorption devices.
Integrated electro-optic modulators in micro-structured LiNbO3
2008
We review recent advances in micro-structuring LiNbO3 crystals and demonstrate the achievement of large bandwidths and lower driving voltages using domain inversion. We will report on a domain engineered Mach-Zehnder modulator for 10Gb/s transmission with ∼2V switching voltage driven by inexpensive Si-Ge drivers.
Metamaterial antenna integrated to LiNbO3 optical modulator for millimeter-wave-photonic links
2015 International Symposium on Antennas and Propagation (ISAP), 2015
We report current research progress on a metamaterial antenna integrated to an optical modulator for millimeter-wave-photonic links. The metamaterial antenna is composed by an array of electric-LC resonators on a LiNbO3 optical crystal. Large millimeter-wave electric field is induced across the capacitive gaps of the resonators due to free-space millimeter-wave irradiation. Optical modulation through Pockels effects can be obtained when light propagates along the capacitive gaps. The integrated device is operated effectively by considering interaction between millimeter-wave and lightwave electric fields along the capacitive gaps. Basic operations of the integrated device for 90GHz millimeter-wave bands are reported and discussed. Optical sidebands with carrier-to-sideband ratio of about ™60dB by millimeter-wave irradiation power of ~20mW can be experimentally measured using optical spectrum analyzer.
Thin layer design of X-cut LiNbO3 modulators
IEEE Photonics Technology Letters, 2000
Microwave-optical velocity matching and 50 impedance matching are difficult to achieve with LiNbO 3 traveling wave modulators. We perform a detailed study (simulations) of the microwave and optical performance characteristics for modulators using thin layer (few micrometers), X-cut LiNbO 3 and find significant improvements in velocity and impedance matching together with a lower .
Micro-structured integrated electro-optic LiNbO 3 modulators
Laser & Photonics Review, 2009
In this paper, we will review the state-of-the-art of LiNbO3 based integrated electro-optic modulators and will show how micro-structuring techniques such as etching, domain inversion and thin film processing can be used to realize new configurations which can take the performance to unprecedented levels. In particular, we will review recent results on the use of domain inversion on a micron scale and we report on the fabrication of a chirp-free modulator having ∼ 2 V switching voltage and bandwidth of 15 GHz designed by placing the waveguide arms of the Mach-Zehnder interferometer in opposite domain oriented regions. We also review some of the new modulation formats (e.g. DQPSK) that can represent an application development of the presented micro-structured devices. Finally, we address the issue of the integration of the modulator chip in a transmitter board comprising tunable laser, bias-control electronics and RF driver. The requirements of integration can even push further the reduction in size of modulator chips, thus making more crucial the use of micro-and nano-structuring techniques.
Integrated RF photonic devices based on crystal ion sliced lithium niobate
Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications VI, 2013
This paper reports on the development of thin film lithium niobate (TFLN™) electro-optic devices at SRICO. TFLN™ is formed on various substrates using a layer transfer process called crystal ion slicing. In the ion slicing process, light ions such as helium and hydrogen are implanted at a depth in a bulk seed wafer as determined by the implant energy. After wafer bonding to a suitable handle substrate, the implanted seed wafer is separated (sliced) at the implant depth using a wet etching or thermal splitting step. After annealing and polishing of the slice surface, the transferred film is bulk quality, retaining all the favorable properties of the bulk seed crystal. Ion slicing technology opens up a vast design space to produce lithium niobate electro-optic devices that were not possible using bulk substrates or physically deposited films. For broadband electro-optic modulation, TFLN™ is formed on RF friendly substrates to achieve impedance matched operation at up to 100 GHz or more. For narrowband RF filtering functions, a quasi-phase matched modulator is presented that incorporates domain engineering to implement periodic inversion of electro-optic phase. The thinness of the ferroelectric films makes it possible to in situ program the domains, and thus the filter response, using only few tens of applied volts. A planar poled prism optical beam steering device is also presented that is suitable for optically switched true time delay architectures. Commercial applications of the TFLN™ device technologies include high bandwidth fiber optic links, cellular antenna remoting, photonic microwave signal processing, optical switching and phased arrayed radar.