Low Noise Balanced Homodyne Detector for Quantum Noise Measurement

• Published in: IEEE access Vol. 10; pp. 27912 - 27916
• Main Authors: Lang, Shubo, Zhang, Shicheng, Li, Xiaolin, Niu, Yueping, Gong, Shangqing
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: balanced homodyne detector; Bandwidth; Circuit boards; Detectors; electromagnetically induced transparency; High gain; Laser noise; Lasers; Low noise; Measurement by laser beam; Noise measurement; Optical noise; Printed circuits; Probes; Quantum noise; Sensors; Shot noise
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2022.3156094

The research of quantum noise in the interaction of laser and atoms plays a critical role in quantum optical experiments. The measurement of quantum noise is mainly based on the balanced homodyne detection method. Here, we reported a balanced homodyne detector with low noise, high gain, and high common-mode rejection ratio (CMRR) at the wavelength of 795 nm. By optimizing the selection of components and printed circuit board (PCB) layout, a minimum electronic noise of −96.7 dBm is obtained. Over the range of 1 MHz to 5 MHz, we get a flat CMRR above 59 dB and a linear gain regime, which can enable a shot noise measurement with the laser power of <inline-formula> <tex-math notation="LaTeX">100~\mu \text{w} </tex-math></inline-formula>. The developed detector can be used in quantum coherent experiments with a weak probe laser of power down to tens of microwatts.