| 摘要 |
PURPOSE:To shorten the length of an absorbing region thereby reducing the reflectance on the absorbing region while restraining the laser oscillation at the low temperature environment thereby enabling the light source for photoinstrumentation with high precision to be provided by a method wherein, at the coupling part of an exciting region with an absorbing region, the relation of the active layer width in the exciting region < the active layer width in the absorbing region is satisfied. CONSTITUTION:A waveguide structure is formed by holding the upper and lower parts of an active layer by clad layers comprising a p type-material and an n type material at low refractive index and having the band gap energy higher than that of the active layer. The title super luminescence diode is formed by coupling two laminated bodies in tandem comprising said bodies functioning as an exciting region (a) having an electrode capable of feeding current and another laminated body functioning as an absorbing region (b) having an electrode but not feeding current or having no electrode at all. At this time, the active layer width at the coupling part of the exciting region (a) and the absorbing region (b) satisfies the relation of the active layer width in the exciting region < the active layer width in the absorbing region. In such a constitution, the active layer width in the absorbing region is made wider than that in the exciting region at the junction part to make the active layer width constant or narrower toward the end of the absorbing region so that the reflectance on the absorbing region side may be sufficiently reduced thereby enabling the laser oscillation at low temperature to be restrained. |
