MONOLITHIC INTEGRATED-OPTIC SENSORS USING WAVE-GUIDE GRATINGS AND QW-DFB LASER

By monolithic integration of a waveguide type grating with a quantum w ell laser, it is possible to construct various ultra-compact and high- performance devices. Since the graded refractive index separately-conf ined single-quantum-well DFB laser is superior in wavelength stability and low-loss passive waveguide formation is made possible by QW disor dering, it is suitable for this type of integration. Examples of optic al integrated circuits, fully functioning with one chip, are provided by a monolithic integrated-optic position/displacement sensor and a mo nolithic integrated-optic disk pickup. Their design, fabrication, and evaluation are carried out. In the former, a photocurrent variation wi th a period of 0.43 mu m is obtained, so that a monolithic optical int egrated sensor fully functioning with one chip was successfully attain ed. (C) 1998 Scripta Technica.