Abstract: An optical amplifier may include an optical fiber to propagate a forward optical signal in a path of propagation of the optical amplifier. The optical fiber may have an input end face that is angled non-perpendicular to the path of propagation. The optical amplifier may include an optical component, in optical communication with the input end face of the optical fiber, to direct a backward optical emission away from the path of propagation.

Abstract: An optical amplifier may include an optical fiber to propagate a forward optical signal in a path of propagation of the optical amplifier. The optical fiber may have an input end face that is angled non-perpendicular to the path of propagation. The optical amplifier may include an optical component, in optical communication with the input end face of the optical fiber, to direct a backward optical emission away from the path of propagation.

Abstract: This specification describes technologies relating to controlling optical amplifiers. In one implementation, an optical amplifier is provided. The optical amplifier includes a light amplifying medium for receiving an input optical signal and outputting an output amplified signal; a first measuring block for measuring a change in power of the input signal; a pump laser for supplying pump light to the light amplifying medium; and an electronic control for controlling the power of the pump light in response to the measured change in power of input signal to provide an output amplified signal having a substantially constant power for one or more changes in the power of the input signal.

Abstract: This specification describes technologies relating to controlling optical amplifiers. In one implementation, an optical amplifier is provided. The optical amplifier includes a light amplifying medium for receiving an input optical signal and outputting an output amplified signal; a first measuring block for measuring a change in power of the input signal; a pump laser for supplying pump light to the light amplifying medium; and an electronic control for controlling the power of the pump light in response to the measured change in power of input signal to provide an output amplified signal having a substantially constant power for one or more changes in the power of the input signal.

Abstract: Systems, methods, and apparatuses are provided for variable gain optical fiber amplifiers. In one implementation, a variable gain optical amplifier is provided. The amplifier includes a first erbium doped fiber configured to receive an input optical signal, a second erbium doped fiber configured to output an output optical signal, a gain flattening filter positioned between the first erbium doped fiber and the second erbium doped fiber, a pump laser configured to provide energy to the first erbium doped fiber and the second erbium doped fiber, a thermo electric cooler configured to control a temperature of one or more of the first erbium doped fiber and the second erbium doped fiber, and a controller configured to adjust an output from the pump laser and a temperature of at least one of the first erbium doped fiber and the second erbium doped fiber to provide a variable flat spectral gain output.

Abstract: Methods and apparatus for amplifying a signal are provided. In one aspect, a method is provided for amplifying an optical signal using an EDFA and includes amplifying an input signal using an EDFA producing an amplified output signal; measuring a pump residual power component of the amplified output signal, and using the measured pump residual power component to adjust a performance of the EDFA.

Abstract: Methods and apparatus for amplifying a signal are provided. In one aspect, a method is provided for amplifying an optical signal using an EDFA and includes amplifying an input signal using an EDFA producing an amplified output signal; measuring a pump residual power component of the amplified output signal, and using the measured pump residual power component to adjust a performance of the EDFA.