Ultra-wideband and High Dynamic Range Cryogenic Electro-Optic Modulators and Switches for Improved Detector System Scalability
Abstract
This DURIP proposal is submitted to the ONR (Dr. Deborah Van Vechten, Email: deborah.vanvechten@navy.mil), in request of funding to acquire a cryogenic probe station and testing apparatus for research in high-bandwidth, low-energy, electro-optic modulators and sw itches.Recently, moderately low drive voltage (1 - 4 volts) electro-optic modulators (EOMs) with about 100 GHz bandwidth (true elec tro-optic RF bandwidth) have been developed and demonstrated using thin-film electro-optic materials. Such EOMs exceed the bandwidth that can be achieved using silicon photonic or III-V photonic modulators, and also offer realization of true phase modulation as we ll as high extinction ratio amplitude modulation through linearized Mach- Zehnder device structures. However, a different class of o ptimized EOM designs can offer maximum instantaneous bandwidths exceeding 0.5 THz and driving voltages as small as a few millivolts. The realization of THz-class bandwidths and ultralow driving voltages in EOMs could be helpful for amplifier-free readout of single flux quantum signals, or to fully exploit the timing resolution supported by certain single-photon detectors where the timing jitte r can now be lessthan 3 ps full-width at half-maximum.Although modern designs and fabrication methods allow additional degrees of freedom which permit precise index matching and impedance definition, the RF loss of the transmission line prevents the EOM perform ance from reaching its fundamental limits under normal conditions. In fact, in devices where performance is governed by RF loss, it is not possible to fully trade off excess bandwidth for lower voltage. We propose that, by modifying and optimizing the design for cryogenic operation, EOMs with long transmission lines can be designed and optimized to achieve ultralow drive voltages while also achieving ultrahigh bandwidth and high extinction ratio. Such traveling-wave EOMs would be relatively unimpacted by the significant stabilization constraints, as well as the linearity and dynamic range limitations of resonant (e.g., microring) EOMs. When brought together, ultrahigh bandwidth, low-voltage EOMs and high photon-efficiency, low-jitter single photon detectors will allow mm-wave s ignal processing and interconnects at the physical limits of detectivity, and this capability, if successfully realized in real devi ces, can enable a wide range of applications relevant to the DoD in communications, sensors, LIDAR, tomography, phased arrays, metro logy, test and measurement, spectrum surveillance and position, and navigation and timing (PNT) applications. Thus, in this DURIP pr oposal, we seek to acquire instrumentation that can be used for research in cryogenic ultra-high bandwidth electro-optic modulator a nd switch devices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2021
- Source ID
- N000142112805
Entities
People
- Shayan Mookherjea
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego