On-chip optical power measurement by optical force

This paper reports a silicon-based micromachined optical power detector with on-chip measurement ability. The optical power is detected by an integrated electron-tunneling displacement transducer, in which optical force is employed as the bridge between optical energy and mechanical energy transition. Compared with the traditional optical power detectors, which are based on photo absorption, the proposed optical power detector has advantages of small size (0.08 mm × 0.3 mm), low thermal noise (0.03 V/°C), large measurement range (> 20 mW) and wavelength independence. Therefore, it has potential applications as high-speed detecting element in silicon-based photonic chips and lab-on-chip systems.