The piezoelectric MEMS (micro-electro-mechanical systems) scanning mirrors are in a great demand for numerous optoelectronic applications. However, the existing actuation strategies are severely limited for poor compatibility with CMOS process, non-linear control, insufficient mirror size and small angular travel. In this paper, a novel, particularly efficient ScAlN-based piezoelectric MEMS mirror with a pupil size of 10 mm is presented. The MEMS mirror consists of a reflection mirror plate, four meandering springs with mechanical rotation transformation, and eight right-angle trapezoidal actuators designed in Union Jack-shaped form. Theoretical modeling, simulations and comparative analysis have been investigated for optimizing two different device designs. For Device A with a 1 mm-length square mirror, the orthogonal and diagonal static tilting angles are ±36.2°@200 V_DC and ±36.2°@180 V_DC, respectively, and the dynamic tilting angles increases linearly with the driving voltage. Device B with a 10 mm-length square mirror provides the accessible tilting angles of ±36.0°@200 V_DC and ±35.9°@180 V_DC for horizontal and diagonal actuations, respectively. In the dynamic actuation regime, the orthogonal and diagonal tilting angles at 10 Hz are ±8.1°/V_pp and ±8.9°/V_pp, respectively. This work confirmed that the Union Jack-shaped arrangement of trapezoidal actuators is a promising option for designing powerful optical devices.

The physics package of a chip-scale atomic clock (CSAC) has been successfully realized by integrating vertical cavity surface emitting laser (VCSEL), neutral density (ND) filter, λ/4 wave plate, ⁸⁷Rb vapor cell, photodiode (PD), and magnetic coil into a cuboid metal package with a volume of about 2.8 cm³. In this physics package, the critical component, ⁸⁷Rb vapor cell, is batch-fabricated based on MEMS technology and in-situ chemical reaction method. Pt heater and thermistors are integrated in the physics package. A PTFE pillar is used to support the optical elements in the physics package, in order to reduce the power dissipation. The optical absorption spectrum of ⁸⁷Rb D1 line and the microwave frequency correction signal are successfully observed while connecting the package with the servo circuit system. Using the above mentioned packaging solution, a CSAC with short-term frequency stability of about 7 × 10⁻¹⁰ τ^−1/2 has been successfully achieved, which demonstrates that this physics package would become one promising solution for the CSAC.

This letter presents a wavelength-selective switch (WSS) based on a polarization-independent transmission grating and a high fill-factor micromirror array. The WSS does not require additional polarization management devices and successfully achieves a low polarization-dependent loss (PDL). A 1 × 4 port WSS has been successfully demonstrated. The maximum driving voltage is about 155 V and an applied overvoltage also illustrates the good reliability of WSS. The test results show that the PDL is less than 0.4 dB. The measured fiber-to-fiber insertion loss (IL) is in range from about 6 to 7 dB and the switching time is about 530 μs .

Fiber collimators are widely used in optical communication components and fiber-optic sensors. Ordinary fiber collimators are made with a circular beam waist radius from $100\mathrm{\mu m}$ to $300\mathrm{\mu m}$. The circular beam waist is too large to switch or shut the beam for certain micro-electro-mechanical system (MEMS) actuators (such as MEMS linear mirrors). In this paper, a dual-fiber collimator with an elliptical spot is proposed to meet the demands of MEMS optical devices. The elliptical spot collimator has been designed and fabricated, the beam waist spot of which is an elliptical spot with a $\mathrm{231.6}\mathrm{\mu m}$ long-axis radius and a $\mathrm{12.87}\mathrm{\mu m}$ short-axis radius, and its coupling loss is $0.37\mathrm{dB}$.