Superfluorescent broadband fiber laser source

US4938556A · kind A · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Michel J. F. Digonnet · Palo Alto, US
• Karen Liu · Montclair, US
• Byoung Y. Kim · Menlo Park, US
• Herbert J. Shaw · Stanford, US
• John J. Fling · Little River, US

Key dates

• Filing date: Dec 7, 1988
• Grant date: Jul 3, 1990
• Expiry date: Dec 7, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/094011
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A superfluorescent broadband fiber laser source comprises a fiber doped with laser material coupled to a multiplexing coupler. In the preferred embodiment, a source of pumping illumination provides pumping light to the doped fiber, and the coupler is adjusted to have a 0% coupling efficiency at the wavelength of the source. The pumping light is sufficiently intense to produce amplified spontaneous emission within the doped fiber, and gives rise to a forward signal and a backward signal. One of the superfluorescent signals is reflected back to the doped fiber by a reflector cemented to one end of the doped fiber or to one end of another fiber through the coupling function of the coupler. The coupler is adjusted to provide complete coupling at the frequency of the lasing light. The temperature dependence of the coupler can be selected to reduce or cancel the temperature dependence of the superfluorescent signal. Other arrangements utilizing the multiplexing properties of the coupler are also described. An all-fiber reflector can also be used.