In-Line Optical MEMS Phase Modulator and Application in Ring Laser Frequency Modulation

Abstract

Optical phase modulators are essential building components in a wide range of applications, for instance, optical communication systems, tunable lasers, optical phase locked loops and optical sensors. The production of in-plane MEMSbased optical phase modulator with self-aligned mirrors, actuator and fiber grooves enables the low cost and easy integration with fiber-based lasers and sensors or photonic microsystems. In this work, we report an in-plane transmission type MEMS-based optical phase modulator fabricated by deep reactive ion etching (DRIE) technology on a Silicon-On-Insulator (SOI) substrate. Detailed optical analysis of the MEMS phase modulator taking into account the diffraction of the single-mode fiber output beam, the asymmetric truncation of the beam by the limited aperture of the micromirrors and the tilt angle of the deeply-etched mirrors is presented. The device layer height of the fabricated SOI wafer is 100 µm and the sidewalls are etched with verticality that is better than 89.98°. The micromechanical system is characterized experimentally using electrical technique and the resonance frequency and quality factor are 11.3 kHz and 163, respectively. The MEMS device is integrated into fiber ring laser (FRL) enabling the achievement of low and high frequency modulation indices. The frequency modulation of the FRL using the presented phase modulator is supported with numerical analysis and experimental results.Index Terms-DRIE, fiber-coupled MEMS, in-plane optical axis, MEMS optical phase modulator, multi-longitudinal mode ring laser, silicon photonics.

Critical analysis of in-plane free-space light beam coupling using photonic curved micromirrors

“…High coupling efficiency with sub-millimeter optical path optical benches was achieved with the use of lenses fibers, 32 the assembly of a ball lens with flat mirrors, 33 the insertion of a fiber rod lens with cylindrical mirrors, 21,34,35 or the hybrid integration of three-dimensional (3D) mirrors that require further assembly or mounting steps. 36,37 The 3D curved silicon micromirrors with in-plane optical axes were recently reported, as a monolithic solution, based on a fabrication process combining deep as well as isotropic etching of silicon.…”

Fast and low loss flexoelectro-optic liquid crystal phase modulator with a chiral nematic reflector

“…Currently, there are a number of technologies available that can be used to modulate the phase of light, this includes optical microelectromechanical systems (MEMS) and liquid crystal (LC)-based spatial light modulators (SLMs). Optical MEMS-based phase modulators containing actuators and micro-mirrors can be engineered to consume very little energy and the devices can be made very small 6,7 . These advantages make them capable of simultaneously steering a large number of optical beams.…”

Optical MEMS accelerometer sensor relying on a micro‐ring resonator and an elliptical disk

“…Several photonic devices are designed based on SOI platforms such as modulators [5], polarisers [6,7], polarisation rotators [8], logic gates [9], tunable photonic filters [10,11], light sources [12], and so on. Among these, photonic tunable filters are one of the practical types due to their capability of extracting light with specific wavelengths, making them suitable for various applications such as the sensing core of MEMS devices [13][14][15].…”