Christian Rembe
TU Clausthal
Institute for Electrical Information Technology
email: rembe@iei.tu-clausthal.de
Abstract:
Squeezed Light Sensors employ entanglements of quantum states of light in order to improve sensing resolution. The technology is successfully implemented in the homodyne interferometers of gravitational wave detectors where squeezed light decreased the noise level the resolution substantially. This is particularly important because Brownian motions generated by laser heating of the mirrors prevent further noise improvement with higher light-power levels. The resolution improvement with squeezed light increased the detected number of events from 2 in the first 6 month to 2 per month and even the merger of neutron stars can now be measured.
The group Applied Metrology at Clausthal University of Technology explores the opportunities of squeezed light in industrial interferometer applications. The talk presents the goals and the first achievements of this research. The doctoral students Mengwei Yu and Lei Xiong work on heterodyne interferometry with squeezed light, which has some special demands that are highlighted in the presentation. First experiments in collaboration with the group of Roman Schnabel demonstrate an improvement of 3.5 dB for the detector-noise level in a heterodyne interferometer with limited measurement-light power [1]. An eye-save heterodyne interferometer at 1550 nm with 10 mW measurement power has a shot-noise limited carrier-to-noise ratio in the light field of already 168 dB, which is even more increased by squeezed light. It is challenging to transfer the potential signal-to-noise ratio to the demodulated signal of a heterodyne interferometer [2]. The talk presents challenges and first promising results.
[1] Yu, M., Gewecke, P., Südbeck, J., Schönbeck, A., Schnabel, R., & Rembe, C., Heterodyne laser Doppler vibrometer with squeezed light enhancement. Optics Letters, 48(21), 5607-5610 (2023).
[2] Yu, M., Schewe, M., Bauer, G., & Rembe, C., Improved demodulated phase signal resolution for carrier signals with small modulation index by clipping and synchronous sampling for heterodyne interferometers. Scientific Reports, 13(1), 8570 (2023).
Short CV:
Christian Rembe received the diploma in Physics from the University of Hanover, Germany, in 1994. From 1994 to 1999, he was a doctoral student at the University of Ulm in Germany where he received a doctor degree in Engineering (Dr.-Ing.). In 1999, he joined the Berkeley Sensor & Actuator Center at the University of California, Berkeley as postdoctoral fellow, supported by a Feodor-Lynen-Scholarship of the Alexander von Humboldt-Foundation and a MacKay Lecturer Fellowship from UC Berkeley. From 2001-2015 he headed the department Development Optics at the Polytec GmbH in Waldbronn, Germany. Since 2015, he is professor for Applied Metrology at the Clausthal University of Technology in Germany. In 2017, he became in addition the director of the Institute for Electrical Information Technology at the TU Clausthal. In 2022 and 2023, he was chair of the management board of the AHMT (working group of university lecturers in metrology of universities in Germany and Austria).
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April 9, 2025
