Patent ID: 8831047

Claim:
A multi-wavelength laser, comprising: a ring multi-wavelength laser having an outer long cavity and an inner short cavity disposed within the outer long cavity; a pair of circulators disposed inside the inner short cavity; a Fiber Fabry-Perot Tunable Filter (FFP-TF) and a semiconductor optical amplifier (SOA) operably connected to the circulator pair within the inner short cavity, the filter providing a feedback path and forming a gain-clamped semiconductor optical amplifier (GC-SOA) having an optical output directing first optical signals to the outer long cavity and an optical input accepting second optical signals from the outer long cavity; a variable optical attenuator (VOA) disposed in the outer long cavity, the variable optical attenuator variably attenuating the first optical signals; a polarization controller disposed in the outer long cavity and operably connected to the variable optical attenuator, thereby controlling polarization of the variably attenuated first optical signals; an optical coupler disposed in the outer long cavity, the optical coupler having an input and a split output; and a filter disposed in the outer long cavity and operably connected to the polarization controller, the filter being configured for filtering the variably attenuated, polarization controlled first optical signals, the filter having an output connected to the optical coupler; and wherein a first portion of the split output from the optical coupler provides a multi-wavelength coherent beam emitted from the multi-wavelength laser, and a second portion of the split output comprises optical signals retained in the cavities.