Novel monolithic widely tunable laser diodes in the 2.1μm wavelength region based on GaSb / AlGaAsSb are
presented. Using the concept of a lateral binary superimposed (BSG) grating structures and multisegment Verniertuning,
stable single-mode output is realized at discrete wavelength channels in the 2060 nm – 2140 nm region. A total
tuning above 80 nm in six channels is demonstrated. In every wavelength channel, the output wavelength can be tuned
by current and temperature. Each wavelength channel offers up to 6 nm of mode hop free tuning, making this novel
widely tunable laser highly attractive as a monolithic light source for multiple-gas sensing or liquid detection purposes.
The wavelength channels can be arbitrarily placed within the material gain allowing BSG lasers to sweep e.g. over
several gas absorption line within 80 nm.
Within a wavelength channel, the widely tunable lasers show DFB like spectral performance with average side-mode
suppression-ratios above 40 dB, output power of up to 15 mW at 25°C. Also temperature and current tuning coefficients
are comparable to those of DFB lasers.
This paper will present an overview of laser concept, performance data and applications.