摘要 |
<p>A source of optical radiation comprises an optical fiber Raman gain medium which is pumped by pump radiation comprising a plurality of spaced apart pump wavelength components. Raman cascading in the gain medium generates an optical output comprising a plurality of output wavelength components, each output wavelength component being derived from a pump wavelength component by one or more Raman shifts. Wavelength components intermediate in the cascade are resonated by use of fiber loops, fiber gratings or dichroic mirrors. Cascading may occur via Raman shifts corresponding to one or more peaks in the Raman gain spectrum of the optical fiber.</p> |