We investigate short pulse illumination of a high-speed extended-InGaAs photodiode at cryogenic temperatures towards its use in control and readout of superconducting qubits. First, we demonstrate high detector responsivity at 1550 nm illumination at 20 mK, a wavelength band unavailable to cryogenic standard InGaAs detectors due to the temperature-dependent bandgap shift. Second, we demonstrate an improved signal-to-noise ratio (SNR) at the shot noise limit for cryogenic short optical pulse detection when compared to conventional modulated continuous-wave laser detection. At 40 uA of photocurrent and a detector temperature of 4 K, short pulse detection yields an SNR improvement of 20 dB and 3 dB for phase and amplitude quadratures, respectively. Lastly, we discuss how short pulse detection offers a path for signal multiplexing, with a demonstration of simultaneous production of microwave pulses at two different carrier frequencies. Together, these advancements establish a path towards low noise and power efficient multiplexed photonic links for quantum computing with a large number of superconducting qubits.
Ultra-low phase-noise microwave generation using a diode-pumped solid-state laser based frequency comb and a polarization-maintaining pulse interleaver
A Simple and Robust Balanced Homodyne Detector for High-Repetition-Rate Pulsed Sources
Università degli Studi di Milano（米兰大学）；Istituto Nazionale di Fisica Nucleare, Sezione di Milano（意大利国家核物理研究所，米兰分部）；Istituto di Fotonica e Nanotecnologie - CNR（光子学与纳米技术研究所-国家研究委员会）
Self-powered InAs nanowire detector arrays for extended-SWIR spectrometry at room temperature
The Australian National University（澳大利亚国立大学）；University of Melbourne（墨尔本大学）；The University of Sydney（悉尼大学）；University of Technology Sydney（悉尼科技大学）；Air Force Research Laboratory（空军研究实验室）
