Compact tunable laser device

摘要

The present invention relates to a compact tunable laser device that can change the oscillation laser wavelength. The laser device includes: a laser diode chip 100 that emits laser light; an optical feedback-partial reflective mirror 500 that feeds some of light emitted from the laser diode chip 100 back to the laser diode chip 100 by reflecting it; a collimating lens 300 that is disposed in a light path between the laser diode chip 100 and the optical feedback-partial reflective mirror 500 and collimates light emitted from the laser diode chip 100; a tunable-selective filter 300 of which the transmissive wavelength changes in accordance with temperature; and a 45°-reflective mirror 400 that changes laser light traveling horizontally to a package bottom into laser light traveling perpendicular to the package bottom, wherein the laser diode chip 100 or the tunable-selective filter 300 is disposed on a thermoelectric element 900 and has an oscillation wavelength changing in accordance with a change in temperature of the thermoelectric element 900.

主权项

1. A semiconductor laser device comprising:
a laser diode chip (100) that emits laser light; a 45°-reflective mirror (400) that changes laser light traveling horizontally to a package bottom into laser light traveling perpendicular to the package bottom and is a partial reflective mirror having a partial reflection/partial transmission characteristic; a collimating lens (200) being disposed along a path of light between the laser diode chip (100) and the 45°-reflective mirror (400), and the collimating lens (200) collimating light emitted from the laser diode chip (100); a tunable-selective filter (300) for changing a transmissive wavelength in accordance with temperature, and the tunable-selective filter (300) being disposed along a path of light reflected vertically by the 45°-reflective mirror (400); an optical feedback-partial reflective mirror (500) being disposed along a path of light reflected by the 45°-reflective mirror (400) and passing through the tunable-selective filter (300), and the optical feedback-partial reflective mirror (500) reflecting some of the laser light passing through the tunable-selective filter (300) back through the tunable-selective filter (300) and toward the 45° -reflective mirror (400) while transmitting a remainder of the laser light which passes through the tunable-selective filter (300); an optical supervisory photodiode (600) being disposed under the 45°-reflective mirror (400) and along a path of light passing vertically through the 45°-reflective mirror (400), and the optical supervisory photodiode (600) receiving a fed laser light reflected from the optical feedback-partial reflective mirror (500) and passing through the 45°-reflective mirror (400) for monitoring an intensity of the fed laser light; a wavelength supervisory photodiode (650) being disposed on a side of the 45°-reflective mirror (400) and along a light path passing horizontally through the 45°-reflective mirror (400), and the optical supervisory photodiode (650) receiving laser light emitted from the laser diode chip (100) which passes through the 45°-reflective mirror (400) and monitoring the intensity of the laser light emitted from the laser diode chip (100); and a wavelength filter (700) being disposed between the 45°-reflective mirror (400) and the optical supervisory photodiode (650) and along the path of light passing through the 45°-reflective mirror (400), and the wavelength filter (700) changing a transmittance in accordance with wavelength; wherein the transmittance of the wavelength filter (700) and the wavelength of light are calculated by comparing optical current flowing through the optical supervisory photodiode (600) and the optical supervisory photodiode (650).