Mode-locked semiconductor laser

DETAILED DESCRIPTION The object of the present invention is to provide a mode-locked semiconductor laser which has few operation limitations in design, a wide range of operating conditions, a low level of jitter, and excellent stability.
To achieve the above-described objects, the present invention comprising: a gain region that emits and amplifies light; and a saturable absorption region that absorbs light emitted by the gain region, thereby causing a reduction of its own absorption coefficient; the gain region is formed from a semiconductor gain material having a two-dimensional or three-dimensional carrier confinement structure having a size on the order of a thermal de-Broglie wavelength, and moreover, the size of the semiconductor of the carrier confinement structure is controlled such that the gain spectrum has discrete peaks at frequency periods of integer powers of the reciprocal of the round-trip time of the optical resonator.
In addition, the present invention comprising: a gain region that emits and amplifies light, and an optical modulation region that modulates the amplitude or phase of light by altering optical characteristics based on externally applied signals from the outside; the gain region is formed from a semiconductor gain material having a two-dimensional or three-dimensional carrier confinement structure having a size on the order of a thermal de-Broglie wavelength, and moreover, the size of the semiconductor of the carrier confinement structure is controlled such that the gain spectrum has discrete peaks at frequency periods of integer power of the reciprocal of the cavity round-trip time of the optical resonator.
The fundamental effects of the invention constructed as described in the foregoing explanation will next be explained.
In recent years, there has been extensive applied research for electronic and optical devices of micro-size, low-dimensional carrier confinement structures, referred to as quantum wires or quantum dots.
These low-dimensional carrier confinement structures are characterized by a confinement size on the order of the thermal de Broglie wavelength