| 摘要 |
PROBLEM TO BE SOLVED: To prevent an optical path of a laser light from being blocked, dissipate heat well even when an active layer of a laser is mounted closely to a silicon substrate and enable mounting of a short-wavelength laser, by breaking a part of a primary face thereby forming a recess, and continuously extending a mirror face to a side wall of the recess. SOLUTION: A silicon substrate 12 is selectively etched by a KOH solution or the like, thereby forming a step part of a flat bottom face 12B and a silicon mirror face 12A of an inclination of 45 deg.. A laser element 14 is mounted at the bottom face 12B. A light radiated from an emission point S is reflected at the silicon mirror face 12A and radiated in a perpendicular direction of the silicon substrate 12. In this case, a recess 12C lower than the bottom face 12B is provided. For instance, when an InGaP/InGaAlP semiconductor laser chip has a thickness T of 120 μm, and a height (x) of the emission point S is 5 μm when the chip is mounted upside down, a depth of the recessed part 12C is 5-50 μm. |
