Optothermal control of gains in erbium-doped whispering-gallery microresonators

Color-detuning-dynamics-based quantum sensing with dressed states driving

Exploring quantum technology to precisely measure physical quantities is a meaningful task for practical scientific researches. Here, we propose a novel quantum sensing model based on color detuning dynamics with dressed states driving (DSD) in stimulated Raman adiabatic passage. The model is valid for sensing different physical quantities, such as magnetic field, mass, rotation and so on. For different sensors, the used systems can range from macroscopic scale, e.g. optomechanical systems, to microscopic nanoscale, e.g. solid spin systems. The dynamics of color detuning of DSD passage indicates the sensitivity of sensors can be enhanced by tuning system with more adiabatic or accelerated processes in different color detuning regimes. To show application examples, we apply our approach to build optomechanical mass sensor and solid spin magnetometer with practical parameters.

Optothermal dynamics in whispering-gallery microresonators

Optical whispering-gallery-mode microresonators with ultrahigh quality factors and small mode volumes have played an important role in modern physics. They have been demonstrated as a diverse platform for a wide range of applications in photonics, such as nonlinear optics, optomechanics, quantum optics, and information processing. Thermal behaviors induced by power build-up in the resonators or environmental perturbations are ubiquitous in high-quality-factor whispering-gallery-mode resonators and have played an important role in their operation for various applications. In this review, we discuss the mechanisms of laser-field-induced thermal nonlinear effects, including thermal bistability and thermal oscillation. With the help of the thermal bistability effect, optothermal spectroscopy and optical nonreciprocity have been demonstrated. By tuning the temperature of the environment, the resonant mode frequency will shift, which can also be used for thermal sensing/tuning applications. The thermal locking technique and thermal imaging mechanisms are discussed briefly. Finally, we review some techniques employed to achieve thermal stability in a high-quality-factor resonator system.

Phonon laser in a cavity magnomechanical system

Using phonons to simulate an optical two-level laser action has been the focus of research. We theoretically study phonon laser in a cavity magnomechanical system, which consist of a microwave cavity, a sphere of magnetic material and a uniform external bias magnetic field. This system can realize the phonon-magnon coupling and the cavity photon-magnon coupling via magnetostrictive interaction and magnetic dipole interaction respectively, the magnons are driven directly by a strong microwave field simultaneously. Frist, the intensity of driving magnetic field which can reach the threshold condition of phonon laser is given. Then, we demonstrate that the adjustable external magnetic field can be used as a good control method to the phonon laser. Compared with phonon laser in optomechanical systems, our scheme brings a new degree of freedom of manipulation. Finally, with the experimentally feasible parameters, threshold power in our scheme is close to the case of optomechanical systems. Our study may inspire the field of magnetically controlled phonon lasers.

Fast light in the generation configuration of stimulated Brillouin scattering based on high-Q micro-cavities

In this article, we reported self-pumped stimulated Brillouin scattering (SBS)-induced fast light in a micro-resonator. The optically induced thermal effect in the micro-resonator will lead to a shift of the dispersion spectrum and make the SBS gain occurred in the anomalous dispersion regime. The group delay could be experimentally optimized from -91.0 microsecond to 2.6 microsecond by changing the modulation frequency in a microsphere with its diameter of 175 μm. The experimental results will benefit applications utilizing anomalous dispersion such as gyroscope.