Tunable optical fiber grating using a memory alloy actuator

The feasibility of a tunable optical fiber grating with a quasi-active and low cost actuator device fabricated by shape memory alloy is investigated. The driving force and displacement of the shape memory alloy actuator are measured. It is found that the SMA actuator with 0.3 mm diameter and 2 mm length driven by 7 V voltage after 5 sec can change the length of the fiber about 60μm, here the strain is about 3%. For the optical communication in the wavelength 1550nm regime, the tunable spectrum width is about 50nm. Therefore, the actuator can use to drive optical fiber grating, it will lead to change the fiber Bragg grating resonance wavelength. This device perhaps plays the key role of tunable optical filter or OADM.