PRESSURE COMPENSATION OF THE TEMPERATURE SHIFT OF THE EMISSION WAVELENGTH OF A DISTRIBUTED-FEEDBACK LASER

A new method of the emission wavelength stabilisation was proposed and developed for a holographic distributed-feedback laser with a dye sol ution. This method was based on pressure compensation of the temperatu re-induced change in the refractive index of the active solution. The compensation was achieved in a hermetically sealed two-section cell: o ne section was filled with the active dye solution and the other, sepa rated from the former by a flexible impermeable membrane, was filled w ith a pressure-compensation liquid. A correct selection of the thermop hysical characteristics of the components ensured that a temperature r ise in both sections increased the pressure more rapidly in the active medium than in the absence of the compensator. This device made it po ssible to stabilise the refractive index of the active medium and to r educe the temperature drift of the emission wavelength by more than tw o orders of magnitude.