Abstract: A variable gain optical amplifier and method for control thereof is provided that includes an amplifier stage having a light pump, and a power source for the pump, and a variable optical attenuator connected to the amplifier stage and having a movable controller that changes attenuation of the amplifier output when moved to a different position. The dynamic controller of the amplifier includes gain detecting circuits that generate signals indicative of input and output signal strengths of the amplifier stage, and a circuit that provides a signal indicative of a position of the attenuator controller, as well as a digital signal processor connected to the outputs of the gain detecting circuits and position indicating circuit. The digital process maintains a selected gain setpoint for the amplifier in accordance with a predetermined relationship between amplifier gain and the signal input and output strengths, and a position of the attenuator controller and signal attenuation.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: A control system and method for a multi-channel optical amplifier is provided that achieves and automatically maintains a selected gain level by controlling the average inversion level of the dopant atoms in the gain fiber. In both the system and the method, a set point average inversion level that corresponds to a gain set point is first selected. A pump light power output necessary to achieve the set point average inversion level is determined from the optical input power, output power, and pump light remnant power. The same parameters used to achieve and maintain the set point average inversion level are also used to determine linear gain per channel which in turn may be used to minimize tilt or ripple in the gain output of the amplifier.

Abstract: According to an illustrative embodiment of the present invention, a method for controlling an optical amplifier is disclosed. The illustrative method includes receiving a portion of an input signal to the optical amplifier; receiving a portion of an output signal from a first amplification stage; receiving a portion of an output signal of the optical amplifier; and adjusting the first amplification stage and a second amplification stage based on the received portions to substantially control the optical amplifier. According to another illustrative embodiment of the present invention, an optical amplifier includes a controller which receives a portion of an output signal from a first amplification stage and a portion of an output signal from the optical amplifier. The controller adjusts the first amplification stage and a second amplification stage based on the received portions of the signals.

Abstract: A variable gain optical amplifier and method for control thereof is provided that includes an amplifier stage having a light pump, and a power source for the pump, and a variable optical attenuator connected to the amplifier stage and having a movable controller that changes attenuation of the amplifier output when moved to a different position. The dynamic controller of the amplifier includes gain detecting circuits that generate signals indicative of input and output signal strengths of the amplifier stage, and a circuit that provides a signal indicative of a position of the attenuator controller, as well as a digital signal processor connected to the outputs of the gain detecting circuits and position indicating circuit. The digital process maintains a selected gain setpoint for the amplifier in accordance with a predetermined relationship between amplifier gain and the signal input and output strengths, and a position of the attenuator controller and signal attenuation.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: A method for compensating for ASE in gain control mode while controlling gain of an optical amplifier, the method including the following steps: (i) obtaining value for input and output power electronic circuitry DC offset; (ii) selecting the following set point values: power set point=0.

Abstract: A dynamic controller for a multi-channel EDFA-type optical amplifier is provided that is capable of providing a substantially tilt-free output over a range of selectable gain set points. The dynamic controller includes a variable optical attenuator coupled between the two amplification coils of the EDFA amplifier, and a control circuit that instructs the attenuator of an amount that each channel should be attenuated to achieve a tilt-free output at a selected gain point. The controller further includes a gain controller and a tilt controller connected to the control circuit of the variable optical attenuator for providing signals indicative of an average amount of per channel attenuation and a relative amount of per channel attenuation necessary to achieve a selected gain set point while reducing or eliminating tilt, respectively.

Abstract: A dynamic controller for a multi-channel EDFA-type optical amplifier is provided that is capable of providing a substantially tilt-free output over a range of selectable gain set points. The dynamic controller includes a variable optical attenuator coupled between the two amplification coils of the EDFA amplifier, and a control circuit that instructs the attenuator of an amount that each channel should be attenuated to achieve a tilt-free output at a selected gain point. The controller further includes a gain controller and a tilt controller connected to the control circuit of the variable optical attenuator for providing signals indicative of an average amount of per channel attenuation and a relative amount of per channel attenuation necessary to achieve a selected gain set point while reducing or eliminating tilt, respectively.

Abstract: An optical fiber amplifier includes an optical system and an electronic controller. The optical system includes: an optical gain medium; at least one pump source coupled to the optical gain medium; an input port for in-coming signal; and an output port for an out-going signal. It also includes an input optical signal tap coupled to a first optical detector; and an output optical signal tap coupled to a second optical detector. The electronic controller is adapted to utilize inputs received from the tabs to control optical power provided by the pump source. The controller includes a user interface that allows a user to control at least one of the following available functions: desired amplifier gain value; amplifier output power value; ASE noise compensation.

Abstract: A method of operating a noise compensating gain controller in an optical amplifier to avoid overshoot of a selected gain level during amplification transients is provided. The first step of the method includes the computation of a difference in the amount of amplification necessary to bring the combination of the signal and noise component forming the optical output to the selected gain level. Next, a computation is made of an adjustment of the amplification difference that is necessary to bring the signal component of the output to the selected gain level at a post-transient, steady-state condition of the optical input. In the final step, the amplification is changed in accordance with the computed difference in the amount of amplification either prior to or simultaneously with the adjustment to this difference.

Abstract: A variable gain optical amplifier and method for control thereof is provided that includes an amplifier stage having a light pump, and a power source for the pump, and a variable optical attenuator connected to the amplifier stage and having a movable controller that changes attenuation of the amplifier output when moved to a different position. The dynamic controller of the amplifier includes gain detecting circuits that generate signals indicative of input and output signal strengths of the amplifier stage, and a circuit that provides a signal indicative of a position of the attenuator controller, as well as a digital signal processor connected to the outputs of the gain detecting circuits and position indicating circuit. The digital process maintains a selected gain setpoint for the amplifier in accordance with a predetermined relationship between amplifier gain and the signal input and output strengths, and a position of the attenuator controller and signal attenuation.

Abstract: According to an illustrative embodiment of the present invention, a method for controlling an optical amplifier is disclosed. The illustrative method includes receiving a portion of an input signal to the optical amplifier; receiving a portion of an output signal from a first amplification stage; receiving a portion of an output signal of the optical amplifier; and adjusting the first amplification stage and a second amplification stage based on the received portions to substantially control the optical amplifier.

Abstract: A method for controlling an optical amplifier is disclosed. The illustrative method includes inputting a set-point to a controller; receiving a portion of an input signal; receiving a portion of an output signal from a first amplifier stage; receiving a portion of an output signal from an attenuation stage; receiving a portion of an output signal from a second amplifier stage and adjusting the first amplifier stage, the second amplifier stage and the attenuation stage based on the received portions to substantially maintain the set-point.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: An optical fiber amplifier includes an optical system and an electronic controller. The optical system includes: an optical gain medium; at least one pump source coupled to the optical gain medium; an input port for in-coming signal; and an output port for an out-going signal. It also includes an input optical signal tap coupled to a first optical detector; and an output optical signal tap coupled to a second optical detector. The electronic controller is adapted to utilize inputs received from the tabs to control optical power provided by the pump source. The controller includes a user interface that allows a user to control at least one of the following available functions: desired amplifier gain value; amplifier output power value; ASE noise compensation.

Abstract: A method for compensating for ASE in gain control mode while controlling gain of an optical amplifier, the method including the following steps: (i) obtaining value for input and output power electronic circuitry DC offset; (ii) selecting the following set point values: power set point=0.

Abstract: A method of operating a noise compensating gain controller in an optical amplifier to avoid overshoot of a selected gain level during amplification transients is provided. The first step of the method includes the computation of a difference in the amount of amplification necessary to bring the combination of the signal and noise component forming the optical output to the selected gain level. Next, a computation is made of an adjustment of the amplification difference that is necessary to bring the signal component of the output to the selected gain level at a post-transient, steady-state condition of the optical input. In the final step, the amplification is changed in accordance with the computed difference in the amount of amplification either prior to or simultaneously with the adjustment to this difference.