Optical microsensors integrated on a silicon chip

The hybrid integration of various optical microcomponents, such as laser diodes, photodiodes, and gratings, on a silicon micromachined substrate by passive optical alignment (optical surface mount technology) has opened up many new possibilities in constructing highly functional, reliable, and low-cost optical microsensors. Using this technology, various microsensors, including a high-resolution encoder that can measure the displacement or revolution angle and a blood flow sensor that can monitor blood flow in human skin, have been developed.