In the paper, the dynamics in the microsecond time-range of thermally induced wavelength shifts in emission spectra of
pulse operated semiconductor lasers is studied. The experimental technique of time-resolved laser spectra mapping,
developed to assess thermo-optical properties of pulse operating lasers is described. The presented technique enables
measurements of the laser mode spectral characteristics at an arbitrarily selected moment within the duration of driving
current pulse. The measured shift of the dominant mode wavelength in the spectrum envelope enables to find out
temperature change of the laser active region. The values of the temperature change have been compared with the ones
numerically calculated employing the finite element method.
In the paper, a technique termed time-resolved spectra mapping, developed to assess thermo-optical properties
of pulse operating lasers, is described. The technique enables measurement of the laser mode spectral characteristic at an
arbitrarily elected moment within the width of the driving current pulse. The measured shift of the central mode
wavelength in the spectrum envelope serves then to determine temperature change of the laser active region. The timeresolved
spectra mapping technique has been found useful in evaluation of the efficiency of heat removal from lasers
mounted in different packages.
External cavity lasers (ECLs) have been around for many years and are recognised as useful tunable narrow line light sources. In this communication we present space resolved spectral characteristics of the ECLs with a standard glass grating and ridge-waveguide broad-contact optical amplifiers (SOAs). The gain of the SOAs was centered in the range of 960 to 980 nm. The spectral characteristics have been measured with an optical spectrum analyzer. The results are compared with the ones obtained after the glass grating was substituted by a grating made from silicon. Application of such silicon gratings can be considered as a first step towards ECLs made fully in a MEMS configuration.