Power selective optical filter devices and optical systems using same
| DWPI Title: Power selective optical filter device used in e.g. self-starting, passively mode-locked fiber laser has output polarizer, which selectively transmits portion of polarization-state-altered signal based on polarization state |
| Abstract: In an embodiment, a power selective optical filter device includes an input polarizer for selectively transmitting an input signal. The device includes a wave-plate structure positioned to receive the input signal, which includes at least one substantially zero-order, zero-wave plate. The zero-order, zero-wave plate is configured to alter a polarization state of the input signal passing in a manner that depends on the power of the input signal. The zero-order, zero-wave plate includes an entry and exit wave plate each having a fast axis, with the fast axes oriented substantially perpendicular to each other. Each entry wave plate is oriented relative to a transmission axis of the input polarizer at a respective angle. An output polarizer is positioned to receive a signal output from the wave-plate structure and selectively transmits the signal based on the polarization state. |
| Use: Power selective optical filter device, such as optical switch structures and optical limiter structures, used in e.g. self-starting, passively mode-locked fiber laser (claimed). |
| Advantage: Provides an all-fiber, achromatic, nonlinear optical switching device that transmits high-peak-power pulses with very low-insertion-loss, but provides bi-directional blocking of low-peak-power and/or continuous wave signals with very high extinction ratio. Enables construction of multi-stage fiber amplifiers having bi-directional isolation of amplified spontaneous emission (ASE) between successive fiber amplifiers, enabling ultra-high-gain pulse amplification. Enables to rigorously divide the ultra-high- gain fiber amplifier into separate, lower gain sections to circumvent small-signal-gain limitations that would otherwise be imposed by continuous wave parasitic lasing associated with in-fiber Rayleigh scattering. Eliminates the need for Faraday isolators, wavelength filters, and amplitude modulators used in current state-of-the-art multi-stage fiber amplifiers, while at the same time providing much higher pulse amplification gain. Eliminates high-peak-power seed sources and high performance q-switches as pre-requisites to successful development of fiber technology for high-energy-pulse regime. |
| Novelty: The optical filter device (400) has an input polarizer (402) having a transmission axis (404), to selectively transmit a portion of an input signal that exhibits a polarization state and a power. A wave-plate structure (200a,200b) is positioned to receive the portion of the input signal. The wave-plate structure includes an output polarizer (406) positioned to receive the polarization-state-altered signal output from the wave-plate structure. The output polarizer selectively transmits a portion of the polarization-state-altered signal based on the polarization state. |
| Filed: 5/4/2012 |
| Application Number: US13464245A |
| Tech ID: SD 11989.3 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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