Low-Voltage Widely Tunable Photonic Crystal Channel Drop Filter in SOI Wafer

We present the design, fabrication, and characterization of an electrostatically tunable optical channel drop filter based on 1-D photonic crystals (PCs) in silicon-on-insulator optical bench platform. Anisotropic etching of the device layer using deep reactive ion etching is used for the realization of the device. The moving parts are released by etching the buried oxide layer using wet etchants. High wavelength sensitivity of 9 nm/100 mV is achieved by moving the two constituent PCs together. Each PC half is moved by more than 250 nm on the application of 4 V effectively shrinking the cavity width by more than 500 nm. A wavelength tuning range of 70 nm with dropped channel bandwidth less than 8 nm in the 1550 nm-1620 nm wavelength range is demonstrated.