High-speed time-domain balanced homodyne detector for nanosecond optical field applications

Silicon photonics-integrated time-domain balanced homodyne detector for quantum tomography and quantum key distribution

“…The low-noise charge and shaping amplifiers following the chip are critical to ensure that the TBHD operates at a low electronic noise level and the output pulse is Gaussian [21,22]. The Op Amps ADA4817 served as the low-noise charge amplifier to integrate the subtracted photoelectrons.…”

“…Thus, the TBHD can be used to detect pulsed signal beams with an intensity of approximately several photons or can act as photon counters [18][19][20]. Conventionally, TBHDs are fabricated using free-space optical devices or fiber optical devices [21,22]. With considerable developments in quantum information and large-scale optical integration technology, realizing the conventional functions of TBHD on an integrated platform is imperative [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39].…”

“…These studies focused on the bandwidth of the detectors. However, TBHDs (use charge and shaping amplifiers), are different from FBHDs (use a transimpedance amplifier) [21,22,42,43]. In the study, we designed and experimentally demonstrated a silicon photonics-integrated TBHD.…”

“…The technical challenge to realize TBHD is achieving a high common mode rejection ratio (CMRR), which is larger than 70-80 dB. Here, the optical intensities and paths of both outputs of the 50/50 coupler are equal, and the response of the two photodiodes to the pulsed beam are matched [21,22]. In our study, to realize a well-performing TBHD on a chip, several methods were employed and demonstrated.…”

Time-domain measurement of ultra-fast intensity difference squeezed pulse pairs generated in fiber

“…To verify the response function of the fast BD can distinguish each pulse pair independently, we estimate the normalized correlation coefficient between the calculated e n values and its N -pulses-shifted values e n−N as it is analyzed in Refs. 16,20 C…”