APPARATUS FOR MEASURING RESONATOR END-SURFACE REFLECTANCE OF SEMICONDUCTOR LASER

摘要

PURPOSE:To facilitate the determination of reflectance of both of resonator end-surfaces even under the cover of protection film by a method wherein the title apparatus is provided with photo detection means each measuring the intensities of laser beams released out of both of resonator end-surfaces, a shutter means opened and closed at the position of shielding reflected laser beams, and a photo detection means measuring the intensity of reflected beams. CONSTITUTION:A reflected beam is shielded by closing the shutter 8, and the ratio X0 of the front photo output P1 of a laser beam irradiating photo detectors 5 and 7 in the case of no feedback beam to the semiconductor laser 1 to its back photo output P2 is measured. Next, the laser beam is reflected on a reflection mirror 4 by opening the shutter 8; then, the ratio Xr of the front photo output P1(r) to the back photo output P2(r) in the case of feedback to the semiconductor laser 1 is measured. Besides, the proportion (r) of the amount of feedback to the amount of front laser emitted beams is measured at the same time by photo detectors 5 and 6. Then, front reflectances R1 and R2 can be determined from these amounts of measurement X0, Xr, and (r).