Patent ID: 6583925
Filing Date: 2003-06-24
Classification: H01S

Abstract:
A rare-earth doped fiber amplifier for providing optical amplification to an applied input signal, Pin, using an optical pump signal, Ppump, the amplifier comprisinga first section of rare-earth doped fiber of length L1, defined as having a first end and a second end, the input signal applied as an input to said second end of said first section; a second section of rare-earth doped fiber of length L2, defined as having a first end and a second end, the input signal applied as an input to said second end of said second section; a first coupler for applying an optical pump signal to the first end of the second section of doped fiber to form a counter-propagation pumping arrangement; a second coupler for removing residual pump power from the second end of the second section of doped fiber; a third coupler for applying the removed residual pump power to the first end of the first section of doped fiber to form a counter-propagation pumping arrangement with the applied residual power pump signal.