Narrow optical bandpass filter via nearly degenerate four-wave mixing
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Updated: Jun 20, 2026
10:42
Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Optics Letters
|August 18, 2009
Abstract:
It is shown that a nearly degenerate four-wave mixing process is capable of yielding a real-time optical bandpass filter. The filter has a large field of view and is capable of providing an amplified bandpass. Moreover, the conjugate nature of the output field can be utilized to increase the signal-to-noise ratio of the device. For a 1-cm interaction length in a nondispersive medium, the optical bandpass at 5000 A can be varied from ~9 GHz down to the linewidth of the exciting laser.
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A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2. The spectrum...
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