PURPOSE: To generate concurrent laser oscillation with two or more wavelengths, by increasing internal loss or mirror loss of a resonator, in a quantum-well semiconductor laser element.
CONSTITUTION: Super-grating-graded-index-wave-guide layers 5 and 7 are interposed between an active layer 6 and an upper clad layer 4, and between the active layer 6 and the lower clad layer 8, respectively, to compose GRIN-SCH structure. Because a stripe edge of the active layer 6 formed on a Zn diffusion region 11 are recessed and projected, the light generated is largely scattered on this region to become the internal loss of the resonator. Moreover, the internal loss of the resonator is increased also by narrowing the width W of this stripe. The similar effect of increasing the mirror loss of the resonator is brought by piling a reflective film having wavelength selectivity and employing diffraction-grating structure on the terminal plane of the resonator or so. When the internal loss of the resonator is thus increased to some degree to form the state in which oscillation is liable to occur on the quantum level higher than the level of conventional oscillatory wavelength, laser oscillation can be generated with the wavelengths corresponding on two or more quantum levels.
FUJIWARA KENZO
TSUKADA NORIAKI
KOJIMA KEISUKE
| JPS62188393A | 1987-08-17 | |||
| JPS61242093A | 1986-10-28 |
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