TUNEABLE, ADJUSTMENT-STABLE SEMICONDUCTOR LASER LIGHT SOURCE AND A METHOD FOR THE OPTICALLY STABLE, LARGELY CONTINUOUS TUNING OF SEMICONDUCTOR LASERS

摘要

The continuously tuneable semiconductor laser light sources with an external resonator portion available hitherto are comparatively complex owing to the fact that, in addition to the degree of freedom necessary for wavelength tuning and optionally a futher degree of freedom necessary for preventing mode jumps, they have further degrees of freedom which have to be maintened alone in a highly sensitive state in optimum positions. This disadvantage is to be overcome by a novel arrangement. The preferably extensively antireflection coated facet of a laser chip is mapped by an optical system onto a reflector, as a result of which the adjustment tolerance is substantially increased by the cat's eye effect and, since the optical system is provided with a high colour length deviation, the wavelengths can be tuned by displacement of given parts of the total system relative to other parts thereof. In this way a tunable semiconductor laser light source which is free from mode jumps and has at most two adjustable degrees of freedom can be produced. The invention further concerns the use of this system inter alia in optical spectroscopy.