Patent ID: 8204349
Filing Date: 2012-06-19
Classification: G02B,H01S

Abstract:
1. Optical apparatus, comprising: an optical fiber having a wavelength of operation, said optical fiber comprising an inner core; a first absorbing ring-shaped core region spaced from and disposed about said inner core, said first absorbing ring-shaped core region being absorbing in that it comprises a first material for absorbing optical energy having the wavelength of operation; a second absorbing ring-shaped core region spaced from and disposed about said inner core, said second absorbing ring-shaped core region being absorbing in that it comprises a second material for absorbing optical energy having the wavelength of operation; said inner core supporting at said wavelength of operation a fundamental mode and, when considered in the absence of said first and second absorbing ring-shaped core regions, at least first and second higher order modes (HOMs) of said inner core; and wherein said first absorbing ring-shaped core region is configured and arranged for suppressing said first HOM of said inner core and said second absorbing ring-shaped core region is configured and arranged for suppressing said second HOM of said inner core.