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Updated: May 24, 2026

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements
Published on: February 28, 2016
Heterodyne detected nonlinear optical imaging in a lock-in free manner
Mikhail N Slipchenko1, Robert A Oglesbee, Delong Zhang
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Abstract:
We report a compact, cost-effective tuned amplifier for frequency-selective amplification of the modulated signal in heterodyne detected nonlinear optical microscopy. Our method improved the signal to noise ratio by an order of magnitude compared to conventional lock-in detection, as demonstrated through stimulated Raman scattering imaging of live cells and tissues at the speed of 2 μsec/pixel. Application of the tuned amplifier to transient absorption microscopy is also demonstrated. The increased signal to noise ratio allowed epi-detected in vivo imaging of myelin and blood in rat spinal cord with high spatial resolution.

