OFS Fitel LLC, a Delaware Limited Liability Company Patent applications |
Patent application number | Title | Published |
20100290106 | Cascaded Raman Fiber Laser System Based on Filter Fiber - A light generation and amplification system includes a length of laser-active filter fiber having a refractive index profile that suppresses unwanted Stokes orders at wavelengths longer than a target wavelength and that has normal dispersion over its operating wavelength. A nested series of reflectors is provided at the fiber's input and output ends, and are configured to provide a nested series of Raman cavities, separated in wavelength by approximately the respective Stokes shifts. The first cavity in the series is a combined cavity that provides laser oscillation due to a combination of ionic gain and feedback at a selected first wavelength and that provides Raman gain to light at the first Stokes shift of the first wavelength when light at the first wavelength has an energy exceeding a Raman scattering threshold. The Raman cavities provide a stepwise transition between the first wavelength and the target wavelength. | 11-18-2010 |
20100284061 | Systems and Techniques for Suppressing Backward Lasing in High-Power Cascaded Raman Fiber Lasers - In a light amplification system and technique, a pump source provides pump power at a source wavelength. The pump power is launched as an input into a cascaded Raman resonator. A wavelength-dependent loss element is connected such that it precedes the cascaded Raman resonator. The wavelength-dependent loss element is configured to transmit light power at the source wavelength with low loss, and to provide high loss at the first Stokes shift. The wavelength-dependent loss element prevents buildup of light power between the pump source and the cascaded Raman resonator, thereby preventing backward propagation of light power back into the pump source. | 11-11-2010 |
20100284060 | Systems and Methods for Cascaded Raman Lasing at High Power Levels - In a light amplification system, a fiber-based oscillator, amplifier, and cascaded Raman resonator are coupled together in series. The oscillator output is provided as an input into the amplifier, the amplifier output is provided as a pumping input into the cascaded Raman resonator, and the cascaded Raman resonator provides as an output single-mode radiation at a target wavelength. A loss element is connected between the oscillator and amplifier, whereby the oscillator is optically isolated from the amplifier and cascaded Raman resonator. A filter is coupled between the isolator and the amplifier for filtering out backward-propagating Stokes wavelengths generated in the cascaded Raman resonator. The oscillator is operable within a first power level range, and the amplifier and cascaded Raman resonator are operable within a second power level range exceeding the first power level range. | 11-11-2010 |