WAVELENGTH TUNABLE MEMS-FABRY PEROT FILTER

摘要

A wavelength tunable gain medium with the use of micro-electromechanical system (MEMS) based Fabry-Perot (FP) filter cavity tuning is provided as a tunable laser. The system comprises a laser cavity and a filter cavity for wavelength selection. The laser cavity consists of a gain medium such as a Semiconductor Optical Amplifier (SOA), two collimating lenses and an end reflector. The MEMS-FP filter cavity comprises a fixed reflector and a moveable reflector, controllable by electrostatic force. By moving the MEMS reflector, the wavelength can be tuned by changing the FP filter cavity length. The MEMS FP filter cavity displacement can be tuned discretely with a step voltage, or continuously by using a continuous driving voltage. The driving frequency for continuous tuning can be a resonance frequency or any other frequency of the MEMS structure, and the tuning range can cover different tuning ranges such as 30 nm, 40 nm, and more than 100 nm.

主权项

1. A tunable MEMS-FP filter comprising:
a semiconductor or dielectric substrate having an upper and a lower face; a fixed reflector attached to the lower face of the substrate, a bottom electrode disposed on the upper face of the substrate, and an AR layer disposed on the upper face of the substrate; a moveable reflector having an upper and a lower face, supported by one or more suspension beams, and comprising a MEMS and multilayer dielectric DBR mirrors and a top electrode disposed on the upper face of the moveable reflector, wherein an air gap is formed between the lower face of the moveable reflector and the upper face of the substrate; wherein an optical cavity is formed between the fixed reflector and the moveable reflector; and a voltage source to supply voltage between the top electrode and the bottom electrode to change the cavity length of the optical cavity.