@article{14980,
  abstract     = {Precision sensing and manipulation of milligram-scale mechanical oscillators has attracted growing interest in the fields of table-top explorations of gravity and tests of quantum mechanics at macroscopic scales. Torsional oscillators present an opportunity in this regard due to their remarked isolation from environmental noise. For torsional motion, an effective employment of optical cavities to enhance optomechanical interactions—as already established for linear oscillators—so far faced certain challenges. Here, we propose a concept for sensing and manipulating torsional motion, where exclusively the torsional rotations of a pendulum are mapped onto the path length of a single two-mirror optical cavity. The concept inherently alleviates many limitations of previous approaches. A proof-of-principle experiment is conducted with a rigidly controlled pendulum to explore the sensing aspects of the concept and to identify practical limitations in a potential state-of-the art setup. Based on this study, we anticipate development of precision torque sensors utilizing torsional pendulums that can support sensitivities below 10−19Nm/√Hz, while the motion of the pendulums are dominated by quantum radiation pressure noise at sub-microwatts of incoming laser power. These developments will provide horizons for experiments at the interface of quantum mechanics and gravity.},
  author       = {Agafonova, Sofya and Mishra, Umang and Diorico, Fritz R and Hosten, Onur},
  issn         = {2643-1564},
  journal      = {Physical Review Research},
  number       = {1},
  publisher    = {American Physical Society},
  title        = {{Zigzag optical cavity for sensing and controlling torsional motion}},
  doi          = {10.1103/physrevresearch.6.013141},
  volume       = {6},
  year         = {2024},
}

@article{14749,
  abstract     = {We unveil a powerful method for the stabilization of laser injection locking based on sensing variations in the output beam ellipticity of an optically seeded laser. The effect arises due to an interference between the seeding beam and the injected laser output. We demonstrate the method for a commercial semiconductor laser without the need for any internal changes to the readily operational injection locked laser system that was used. The method can also be used to increase the mode-hop free tuning range of lasers, and has the potential to fill a void in the low-noise laser industry.},
  author       = {Mishra, Umang and Li, Vyacheslav and Wald, Sebastian and Agafonova, Sofya and Diorico, Fritz R and Hosten, Onur},
  issn         = {1539-4794},
  journal      = {Optics Letters},
  keywords     = {Atomic and Molecular Physics, and Optics},
  number       = {15},
  pages        = {3973--3976},
  publisher    = {Optica Publishing Group},
  title        = {{Monitoring and active stabilization of laser injection locking using beam ellipticity}},
  doi          = {10.1364/ol.495553},
  volume       = {48},
  year         = {2023},
}

@article{13264,
  abstract     = {We build a parametric amplifier with a Josephson field-effect transistor (JoFET) as the active element. The resonant frequency of the device is field-effect tunable over a range of 2 GHz. The JoFET amplifier has 20 dB of gain, 4 MHz of instantaneous bandwidth, and a 1-dB compression point of -125.5 dBm when operated at a fixed resonance frequency.

},
  author       = {Phan, Duc T and Falthansl-Scheinecker, Paul and Mishra, Umang and Strickland, W. M. and Langone, D. and Shabani, J. and Higginbotham, Andrew P},
  issn         = {2331-7019},
  journal      = {Physical Review Applied},
  number       = {6},
  publisher    = {American Physical Society},
  title        = {{Gate-tunable superconductor-semiconductor parametric amplifier}},
  doi          = {10.1103/PhysRevApplied.19.064032},
  volume       = {19},
  year         = {2023},
}