External Cavity Wideband Tunable Laser with Dual Laser Gain Media Coupled by a Polarization Beam Combiner

摘要

The invention relates to an external cavity wideband tunable laser with dual laser gain media coupled by a polarization beam combiner. The laser comprises a first laser gain medium, a first laser cavity end mirror arranged on the first laser gain medium, a first intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, an intracavity reflection mirror, an etalon and a total reflection mirror which are arranged on the opposite side of the tunable acousto-optic filter from the intracavity reflection mirror inside a laser cavity. The laser further comprises a second laser gain medium, a second laser cavity end mirror arranged on the second laser gain medium, a second intracavity collimating lens, a passive polarization rotator, and a polarization beam combiner for coupling the output light beams emitted from the first laser gain medium and the second laser gain medium, a radio frequency signal source, pumping sources for the two laser gain media, an active optical phase modulator drive source and a laser drive control circuit. The invention can significantly expand the output spectrum range of a single tunable laser to cover C and L band. The laser has reliable performance with stable output and compact size, low cost for volume production and easy installation.

主权项

1. An external cavity wideband tunable laser with dual laser gain media coupled by a polarization beam combiner comprising: a first laser gain medium, a first laser cavity end mirror arranged on the first laser gain medium, a first intracavity collimating lens for collimating the light beam emitted from the first laser gain medium, an active optical phase modulator, a tunable acousto-optic filter, an intracavity reflection mirror, which are all arranged sequentially, an etalon and a total reflection mirror, which are arranged on the opposite side of the tunable acousto-optic filter from the intracavity reflection mirror, the laser further comprises:
a second laser gain medium, a second laser cavity end mirror arranged on the second laser gain medium, a second intracavity collimating lens for collimating the light beam emitted from the second laser gain medium, the optical axes of second laser gain medium and the second intracavity collimating lens arranged in vertical direction to the optical axes of the first laser gain medium and the first intracavity collimating lens; a passive polarization rotator arranged behind the first intracavity collimating lens to rotate the polarization direction by 90 degrees of the light beam outputted from the first intracavity collimating lens, and a polarization beam combiner aligned with an angle of 45 degrees with respect to the output light beams of the first intracavity collimating lens and the passive polarization rotator to pass the light beam from the first intracavity collimating lens and to reflect the light beam from the second intracavity collimating lens; an active polarization rotator arranged on the output light path of the laser and used for rotating the polarization state of the output light beam from the second laser gain medium by 90 degrees so that the polarization state of the output light beam is the same as that of the output light beam from the first laser gain medium: a radio frequency signal source for providing radio frequency energy for the tunable acousto-optic filter and for adjusting the oscillation wavelength of the laser resonant cavity by changing RF frequency; and pumping sources for the two laser gain media, an active optical phase modulator drive source, an active polarization rotator drive source and a laser drive control circuit.