Application of an Automotive Relay as Optical Beam Shutter

Laser beam modulation is often required in many applications. Continuous wave (cw) gas lasers can be modulated only with devices external to the resonant laser cavity. Beam modulation can be achieved with several types of instruments like rotating wheel choppers, rotating blade shutters and electromagnetically actuated iris. In this work, an automotive relay model DNI0102 was modified to operate as an optical beam shutter. The electrical and optical characterization of the modified device are presented. The intrinsic resistance and inductance of the relay coil was measured as 80  \(\Omega \) and 117.1 mH, respectively. The switching time obtained with the use of a 0.65 mm helium-neon gas laser beam was approx. 250  \({\upmu }{\text {s}}\) . The DNI0102 relay electrical characterization must substantiate and enforce future discussions about the relation between coil inductance and relay’s switching time performance as shutters devices. In conclusion, the built device showed a fast switching speed that fits the demands of mostly experimental applications.