Optical high-frequency pulse generation with wavelength tunability by using a DBR laser with vernier-type gratings

An optical high-frequency pulse generation method with wavelength tunability is presented by taking advantage of vernier-type gratings in a distributed Bragg reflector laser diode. Experimental results showed that sinusoidal optical pulses, whose lasing wavelengths were tunable, were created with repetition frequencies around 30 GHz. The widths of the radio frequency spectra, furthermore, were drastically reduced by means of mode locking with externally injected optical pulses.

Very SHORT optical pulse generation is an indispensable function to realize future all-optical network systems. For this purpose, mode-locked lasers [1] as well as self-pulsating distributed feedback lasers [2] are very promising candidates, which have been oscillated at very high repetition frequencies of 160 GHz beyond [3]– [5]. Fig. 1. Schematic illustration of (a) a multielectrode DBR laser and (b) its waveguide alignment. For more complete construction of reconfigurable all-optical networks, furthermore, a device, which combines optical time-division multiplexing (OTDM) with dense wavelength-division multiplexing (DWDM), should be considered. In this letter, we present a new method of wavelength tunable optical pulse generation, where a well-designed wavelength tunable distributed Bragg reflector (DBR) laser was utilized for the experimental demonstration.