US 5,177,749 A · Semiconductor laser device

Abstract

A semiconductor laser device includes a semiconductor laser element having a quantum well structure active layer having n levels of quantum states (n.gtoreq.2) from the first quantum level to the n-th quantum level in which the front facet reflectivity and the rear facet reflectivity are asymmetrical so that oscillation can occur at the n-th quantum level, a reflecting mirror having a reflectivity that causes oscillation of the semiconductor element to occur at a quantum level lower than the n-th quantum level, and a reflecting mirror moving unit for positioning the reflecting mirror in the neighborhood of the front facet or the rear facet of the semiconductor laser element. Therefore, a semiconductor laser device which can oscillate at two or more wavelengths with a simple construction is obtained.

Claims8

Dependent claims

A semiconductor laser device comprising:

a semiconductor laser element having an active layer comprising a quantum well structure having n energy levels, where n.gtoreq.2, from a first quantum level to an n-th quantum level and opposed front and rear facets having respective reflectivities, the front facet reflectivity and the rear facet reflectivity being asymmetrical so that oscillation can occur at the n-th quantum level;
and
a reflecting mirror element comprising a material having a refractive index that varies with injection of charge carriers into said material, for altering the reflectivity at one of said front and rear facets and disposed opposite one of said front and rear facets, said semiconductor laser element oscillating at an arbitrary quantum level from the first quantum level to the n-th quantum level.

Dependencies are inferred from the claim text.

Semiconductor laser device

Life of this patent

Semiconductor laser device

Life of this patent

Abstract

Claims8