We have investigated in detail the continuous-wave (cw) and mode-locked performance of a diode-pumped Cr:Nd:GSGG laser. State-of-the-art single-mode and multimode laser diodes around 665 nm were used as pump sources. In cw operation, we have demonstrated lasing thresholds as low as 14 mW, slope efficiencies as high as 23.4%, and output powers up to 738 mW. The free running emission wavelength was 1061 nm. Lasing could also be obtained at 1051, 1058, 1065, 1068, 1072, 1103, and 1111 nm lines. A saturable Bragg reflector was used to initiate and sustain mode-locking where the Cr:Nd:GSGG laser produced 6-ps-long pulses around 1061 nm with an average power of 160 mW. The repetition rate was 142.65 MHz, resulting in pulse energies of 1.1 nJ and peak powers of 175 W. An off-surface optical axis quartz birefringent filter (BRF) was inserted inside the laser cavity at Brewster's angle to obtain two-color cw and mode-locked laser operation at the 1051 and 1058 nm and 1058 and 1061 transition pairs, resulting in cw powers up to 60 mW and cw mode-locked average powers up to 45 mW. Unlike many other methods applied for two-color mode-locked laser operation, usage of the BRF enabled regulation of the ratio of the power in each line by fine adjustment of its rotation angle. The method could potentially be used for other gain media as well, which could simplify development of multicolor solid-state laser systems.

We demonstrate a solid-state optomechanical resonator driven into oscillation mode for high resolution acceleration sensing. The low-frequency performance is greatly increased to 70^g/Hz1/2 at 10-3 Hz when the resonant wavelength detuned pump laser is stabilized.

Recent scientific and technological advances have enabled the detection of gravitational waves, autonomous driving, and the proposal of a communications network on the Moon (Lunar Internet or LunaNet). These efforts are based on the measurement of minute displacements and their corresponding force transduction, which enables acceleration, velocity, and position determination for navigation. State-of-the-art accelerometers use capacitive or piezoresistive techniques and micro-electromechanical systems (MEMS) via integrated circuit (IC) technologies to drive transducers and convert their output for electric readout. In recent years, laser optomechanical transduction and readout have enabled highly sensitive detection of motional displacement.Here the theoretical framework is further examined for the novel mechanical frequency readout technique of optomechanical transduction when the sensor is driven into oscillation mode. Theoretical and physical agreements are demonstrated, and the most relevant performance parameters are characterized by a device with a 1.5 mg Hz −1 acceleration sensitivity, a 2.5 fm Hz −1/2 displacement resolution corresponding to a 17.02 µg Hz −1/2 force-equivalent acceleration, and a 5.91 Hz nW −1 power sensitivity, at the thermodynamical limits. In addition, a novel technique is presented for dynamic range extension while maintaining the precision sensing sensitivity. This inertial accelerometer is integrated on-chip and enabled for packaging, with a laser-detuning-enabled approach.

Here we present an optomechanical inertial accelerometer with resonant frequency readout, where the transducer's core photonic crystal has been designed to provide linear input-output dependence, which is further enhanced by our integrated linearization model.