Miniature packaged external-cavity semiconductor laser with 50 GHz continuous electrical tuning range

Miniature, packaged, grating-external-cavity lasers have been developed for use in PSK. and DPSK coherent transmission systems at 1.5μm. The outside dimensions of the package are 30 × 30 × 50 mm and the optical cavity length is nominally 30 mm, resulting in a spectral linewidth < 100 kHz. The lasing wavelength is mechanically adjustable over the range 1510–1560 nm and electrically tunable over a range of 0.8 nm. With appropriate control of the grating piezos, a continuous (hop-free) tuning range of 50 GHz (0.4 nm) can be obtained.