Optical chamber module assembly

摘要

A gas sensor system includes a laser module, optical chamber module, and a gas sensor cell. The laser chamber module includes two laser light sources producing laser light emissions at wavelengths λ1 and λ2, respectively. Each beam path optionally includes an optical isolator. The beam paths enter the housing of the optical chamber module where they are combined into a third wavelength, λ. The housing of the optical chamber module includes an inlet and an outlet for passing a selected target gas. The gas sensor cell mates to the inlet of the housing. The target gas passes through the adjacent gas cell and into the optical chamber module through the inlet. The target gas exits the optical chamber module through the outlet. Within the optical chamber module, a nonlinear crystal receives the laser light emissions at wavelengths λ1 and λ2 and generates the third wavelength, λ3. The wavelength λ3 is selected to be at the mid-IR spectral absorption feature of the target gas, i.e. a strong absorption line in the vibrational spectrum of a specific chemical species that is targeted by the gas sensor. The third wavelength λ3 is generated by the interaction of the electric fields of the two laser emissions. The nonlinear optical crystal may be periodically poled, and configured to frequency-convert the first and second laser beams. The residual light from the two laser sources is removed from the mid-infrared beam with an absorptive and/or reflective optical filter.

主权项

1. An assembly comprising:
a laser light source including:
a first laser emitting a first laser beam having a wavelength λ1 in a range of about 1500 nm to about 1650 nm;a second laser emitting a second laser beam having a wavelength λ2 in a range of about 1120 nm to about 1200 nm;a first optical isolator receiving the first laser beam; anda second optical isolator receiving, the second laser beam; an optical chamber module including a housing having, an inlet and an outlet, including a mid-IR transparent window proximate the inlet, the housing including:
a nonlinear crystal, operative to receive the first beam and the second beam, generating a third beam having a wavelength λ3 where λ3=(λ1λ2)/(λ1−λ2);an optical filter, receiving the third beam, removing residual light related to the first and the second beam;a first series of steering mirrors directing the third beam through the mid-IR transparent window:a pickoff mirror, receiving an attenuated beam, positioned proximate the mid-IR transparent window, reflecting the attenuated beam;a photo-detector; anda second series of steering mirrors, receiving the attenuated beam and directing the attenuated beam to the photo-detector; and a multiplexer, interposing the first optical isolator and the non linear crystal and interposing the second optical isolator and the non linear crystal.