Abstract: A method and apparatus for controlling transients in an optical signal propagating along an optical fiber path interconnecting a plurality of network elements employs a power threshold to determine an appropriate response given a change in optical signal power.

Abstract: An amplification medium simulation apparatus comprises a basic data retaining unit 21, an input signal beam information retaining unit 22, and a simulation executing unit 31 approximating and calculating an output signal beam power at each signal beam wavelength outputted from the amplification medium involving a fluctuation in ion population at the metastable energy level in the amplification medium due to input of the input signal beam, by using contents retained in the basic data retaining unit 21 and the input signal beam information retaining unit 22, and outputting a result of calculation as a result of simulation of performance of the amplification medium.

Abstract: An optical amplifier, provided in a WDM transmission system, contains an amplification medium for amplifying WDM light, a measurement part for measuring at least one input optical power of the WDM light on both input and output sides of the amplification medium, a variable gain equalizer for variably setting a passing-wavelength characteristic, a database for holding data representing wavelength characteristics that respectively correspond to transmission line types, an arithmetic part for computing an inverted passing-wavelength characteristic resulting from a passing-wavelength, based on an acquired transmission line type, the optical power measured by the measurement part, and the data held in the database, and a setting part for setting a passing-wavelength characteristic of the variable gain equalizer, based on the inverted passing-wavelength characteristic computed by the arithmetic part, and with this, capable of controlling optical filters more quickly and amplifying optical signals more efficiently i

Abstract: In the WDM systems, the OSNR and the signal loss among the optical signals are substantially minimized at the receiving terminal to combat the SRS effects. An equal amount of the signal loss is expected for every span in the transmission path so that the optical amplifier gain tilt is not affected among a number of wavelength frequencies in the optical signal. This is accomplished by controlling the amplification process according to a feedback from the monitoring units for monitoring the optical signal.

Abstract: Circuits and systems for use in monitoring and adjusting an optical signal strength of an optical data transmission system. A closed feedback loop which automatically controls an optical device's output uses an analog operational amplifier based circuit instead of a conventional microprocessor that uses complex calculations. The parameters of the operational amplifier circuit are monitored and controlled by a microcontroller to provide flexible operational settings. The analog circuit containing discrete analog components is used as a power meter for measuring an optical power signal strength of an optical signal. The optical signal is tapped by an optical coupler and the signal is received by a photodetector. The output of the photodetector is received by the analog circuit which produces an intermediate signal based on the level of optical power in the optical signal. The intermediate signal is used to control an optical device.

Abstract: An optical fiber propagates and amplifies a second signal light that is a wavelength-multiplexed signal of a first signal light of a plurality of wavelengths and a reference light that is out of a wavelength range of amplification. An excitation light source outputs an excitation light for amplifying the second signal light. A beam splitter splits a portion of the second signal light into the first signal light and the reference light. A signal light level detecting unit detects a level of the first signal light. A reference light level detecting unit detects a level of the reference light. A signal level setting unit calculates a target value for constantly maintaining a Raman gain, and controls the output level of the excitation light in such a way that the first signal level matches with the target value.

Abstract: An optical fiber amplifier features an optical amplifying section for amplifying an inputted optical signal. A sampling section is provided for shunting part of the optical signal amplified by the optical amplifying section and detecting a first test light belonging to a short wavelength band and a second test light belonging to a long wavelength band. An input power control circuit serves to compare respective powers of the first and second test lights and then outputs a control signal for controlling an input power of the optical signal inputted to the optical amplifying section according to the power differential of the first and second test lights. An output power control circuit derives an output power of the optical amplifying section from the power of the optical signal shunted at the sampling section and also controls the optical amplifying section so that the output power of the optical amplifying section attains a predetermined value.

Abstract: Pump energy with a wavelength which is below the wavelength of an optical signal is fed into a transmission section from a pump laser via a coupler. The received optical signal is attenuated with increasing pump power with signals having higher frequencies being more strongly damped.

Abstract: The gain control circuit controls the amplification ratio of EDFA based on the results of having measured the input power monitor which monitors the EDFA input optical level which amplifies light and of having measured the output power monitor which monitors the output optical level. The optical pre-amplifier receives a notice of the number of wavelengths from a fore node and a notice of whether the optical post-amplifier of a fore node is in normal operation by a supervisory control signal, and changes over the gain control circuit to either the ALC or AGC mode. When the number of wavelengths changes while the optical pre-amplifier is operating in the ALC mode, the optical pre-amplifier is controlled in the AGC mode using the backed-up amplifier gain. Also, the gain value when the optical pre-amplifier is in routine operation is backed up in an amplifier gain back-up unit and an back-up unit.

Abstract: The invention relates to a method for automatic dynamic gain control in optical Raman amplifiers and an optical Raman amplifier adapted for the same. The present invention has found that in multiple pump Raman amplifiers a substantially linear relationship exists between total amplified signal power and pump power for each of different wavelength pumps, in order to maintain an original gain profile and gain levels for an optical link with a fully loaded channel configuration, in response to dropped channels. In accordance with the method, and an amplifier programmed to practice the method, a set of pump power values and signal level values required to maintain the characterized gain profile and gain levels for a plurality of channel loading configurations are pre-established for the each pump wavelength. A linear function from each set of pre-established values is derived for each pump wavelength.

Abstract: A controller for an optical amplifier and a method for controlling an optical amplifier are 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 optical amplifying apparatus is composed of a light amplifying part for amplifying light and an input light controlling part for inputting, to the light amplifying part, probe light that serves to adjust the optical power of input light of the optical amplifying part. Receiving light having constant optical power, the optical amplifying part operates stably. In particular, the optical amplifying part stably operates even in a case where input light is a WDM optical signal and the number of multiplexed optical signals increases or decreases. The OADM of the present invention comprises such an optical amplifying apparatus.

Abstract: Wavelength multiplexed light is amplified by first and second EDFs. Gains of the first and the second EDFs are respectively held to be predetermined values by first and second AGC circuits. Between the first and the second EDFs, a variable attenuator is arranged. A loss in the variable attenuator is controlled by an ALC circuit so that output power is held to be a predetermined value instructed by a supervisory control signal. Respective time constants of the first and the second AGC circuits are sufficiently short in comparison with the response times of the first and the second EDFs. The time constant of the ALC circuit is sufficiently long in comparison with the time period required to transmit the supervisory control signal to each optical node.

Abstract: There are provided a plurality of optical adjusting sections, a wavelength-multiplexing section, and a control section. The plurality of optical adjusting sections, which are provided for respective wavelength bands, amplifies light beams in the respective wavelength bands. The wavelength-multiplexing section wavelength-multiplexes amplified light beams in the respective wavelength bands. The control section controls the outputs of the respective optical amplifying sections so that optical powers of the respective wavelength bands will become approximately identical at a predetermined point when wavelength-multiplexed light of the light beams in the respective wavelength bands travels to the predetermined point. This configuration makes it possible to eliminate optical power deviations between wavelength bands that would otherwise occur when an optical signal of a plurality of wavelength bands is transmitted, and to thereby make optical SNRs uniform.

Abstract: A controlling apparatus and a controlling method for a wavelength division multiplexing optical amplifier to reduce the controlling error due to noise light included in the monitoring light. The controlling apparatus branches, by a photocoupler, a portion of WDM signal light amplified by a light level controlling part and separates the branched light into groups of even-numbered channel components and odd-numbered channel components using a wavelength channel separate filter. Monitor signals corresponding to the light powers of the even-numbered group and odd-numbered group, respectively, are generated by respective photoelectric converting parts and LPF's. One of the monitor signals, which corresponds to one of the even-numbered group and the odd-numbered group, is selected by a monitor signal selecting/controlling part and then sent to a comparator.

Abstract: A method and apparatus for controlling transients in an optical signal propagating along an optical fiber path interconnecting a plurality of network elements employs a power threshold to determine an appropriate response given a change in optical signal power.

Abstract: This invention provides a gain control device and method for an erbium doped fiber amplifier that is capable of maintaining a constant gain irrespective of the intensity variation of the input signal light.

Abstract: An improved optical power transient control scheme is provided for optical amplifiers used in long haul, high capacity DWDM optical networks. The optical power transient control scheme employs a combination of feed-forward and feedback control mechanisms to adjust the pump laser current of an amplifier. In this way, the optical power transient control scheme allows for very fast detection of transient changes in optical input power and fast control settling time with minimal optical power degradation.

Abstract: A system and method for controlling alignment of laser center wavelengths and filter passband center wavelengths in optical amplifiers for purposes of providing automatic gain control and eliminating unwanted noise. The system and method exploits a wavelength-locked loop servo-control circuit and methodology that enables real time mutual alignment of a laser pump signal having a peaked spectrum function including a center wavelength and a wavelength selective device such as an optical filter implementing a peaked passband function including a center wavelength in an optical amplifier.

Abstract: Optical signals (multi-wavelength light) are guided to an EDF. The EDF is supplied with pump light generated by a first and a second pump light sources. Dummy light is generated by a dummy light source and supplied to the EDF. The wavelength of the dummy light is shorter than a wavelength range in which the optical signals are allocated.

Abstract: A Raman fiber amplifier includes: a transmission fiber; at least one optical pump providing optical pump power to the transmission fiber; and at least one pump power detector; at least one signal detector detecting signal power propagating through the transmission fiber. The Raman fiber amplifier also includes a controller that adjusts the pump power provided by the pump to adjust, gain, or signal power provided by this Raman fiber amplifier.

Abstract: A system and method for controlling optical amplifier pumps. A path average intensity detector is provided for detecting a path average intensity for transmitted optical signals. In response to the detected path average intensity or a variation in path average intensity, a pump parameter controller dynamically adjusts at least one pump parameter of at least one amplifier to achieve a desired path average intensity.

Abstract: Optical network equipment is provided. The optical network equipment may include optical amplifiers. Control units may be used to control components in the equipment such as gain stage pump lasers. Sensor data may be obtained from sensors in the equipment. The control units may store the sensor data and control data and other information on the operation of the equipment. The stored data may be used in troubleshooting, network maintenance, and set up procedures. Data may be saved when a data storage command is received by the equipment or may be saved when data storage trigger criteria are satisfied. A user may be provided with the ability to customize the trigger criteria and the data storage parameters.

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: Optical amplifiers and optical network equipment are provided that have optical gain stages for amplifying optical signals on a fiber-optic communications link. The optical gain stages may be based on optically pumped fiber such as rare-earth-doped fiber. The fiber may be optically pumped using laser diode pumps. A control unit may be provided in the amplifiers or other equipment to control the laser diode pumps. Optical monitors may be used to measure the optical signals in the amplifiers or other equipment. The pump powers of the laser diode pumps may be adjusted in real time by the control unit based on the measured optical signals to suppress gain transients due to input power fluctuations on the link. To minimize the impact of pump-induced noise, the control unit may avoid operating the laser diodes at powers at which the laser diodes are most susceptible to mode partition noise.

Abstract: An optical amplifier includes an optical amplifying medium having a multiplexed light input thereto and providing an output of amplified multiplexed light, an excitation source which excites the optical amplifying medium; and at least one of a first monitor for monitoring the amplified multiplexed light from the optical amplifying medium and a second monitor for monitoring the multiplexed light input to the optical amplifying medium. An operation amount of the excitation source for the optical amplifying medium is controlled using a monitoring result output from at least one of said first and second monitors.

Abstract: A switchable dynamic gain-flattened optical amplifier with wide adjustable gain range is provided. Optical signals are amplified through common amplification such that the gain is approximately common to all optical signals. Further, gain specific amplification is then achieved through distinct amplification wherein the optical signal is routed through one of N parallel amplification paths each having its well-designed gain. The amplifier makes use of a control circuit to self-adjust quickly and respond to changes in input conditions, operating conditions of the optical amplifier and gain requirements while maintaining gain flatness and a low noise figure (NF) over a broad optical bandwidth and a wide range of gain levels. The optical amplifier is highly desirable in dense wavelength-division-multiplexed (DWDM) systems for responding to changes in operating conditions due to link loss, pump deterioration, channel add/drop, and network reconfigurations.

Abstract: Light signals of first to n-th bands amplified en bloc undergo proper attenuation through an adjustable optical attenuator in conformance with attenuation in an optical fiber connected to input of an optical amplifying repeater apparatus, whereon the light signals are demultiplexed or separated into individual bands and amplified by first to n-th fixed-gain optical amplifiers (#1, . . . , #n) each having a high fixed gain in the respective bands to be subsequently multiplexed by an optical multiplexer and then sent out onto a transmission line. A monitoring light branching device extracts a part of light power of a specific monitoring wavelength, which is then fed to an adjustable attenuator control circuit which controls the attenuation factor of the adjustable optical attenuator so that the light power of the specific wavelength remains constant. The gain of the optical amplifying repeater apparatus at the specific wavelength can thus be determined.

Abstract: An optical output signal of an optical amplifier 1 branched by an optical divider/splitter 2 is separated by an optical demultiplexor 3 into different paths □1 to □n in accordance with the wavelength, and the level of each different wavelength component is adjusted under the control of an optical attenuator control circuit 9 on the basis of a transmission wavelength information notified through a transmission wavelength information input terminal 14. At this time, in the path corresponding to the wavelength transmitted, the attenuation amount of an optical attenuator is controlled to a minimum level, and in the path corresponding to the wavelength other than the wavelength transmitted, the attenuation amount of an optical attenuator is controlled to a maximum level. After the level adjustment, the different wavelength components are combined by an optical multiplexor 5, and the level of the combined signal is detected by a photo diode 6.

Abstract: The present invention aims at providing a WDM optical communication system adapted to avoid reduction of signal light power per one wavelength included in output light of an ALC operating optical amplifying device, to thereby improve transmission characteristics of WDM signal light.

Abstract: An optical amplifier for fiber-optic communications systems is provided. The optical amplifier may have variable optical attenuators for adjusting the power on each of multiple input channels. A multiplexer may be used to combine the input channels onto a single optical path. A gain stage may be used to provide optical gain for the optical signals on the optical path. A control unit may be used to control the variable optical attenuators and the gain stage to produce a desired spectrum.

Abstract: An optical node and method for operation in an ultra long haul backbone network that provides DWDM optical transmission and wavelength networking functionalities are disclosed. The optical node is designed with capabilities for amplification, dispersion compensation, and add/drop functionalities. In one embodiment, three erbium-doped fiber amplifier (EDFA) are cascaded using low nonlinearity and low loss dispersion compensating module (DCM).

Abstract: An optical fiber amplifying apparatus is provided with an optical fiber for amplifying input signal lights, a heating/cooling element for heating or cooling the optical fiber, and a temperature control circuit for controlling the element. The circuit effects control so as to keep the optical fiber at a prescribed temperature on the basis of the output of a temperature sensor. The circuit also controls the heating/cooling element so as to keep the level(s) of at least one signal light extracted out of wavelength-multiplex signal lights at a prescribed value. The circuit can compute the gain from the input and output levels of one or more signal lights, and control the element so as to keep this gain within a prescribed range.

Abstract: The invention includes a method for controlling amplifier output power in an optical communications network. A first transmission parameter is determined at a first amplifier. In an exemplary embodiment, the first transmission parameter is a composite express signal to noise ratio. The total output power of a downstream amplifier is adjusted in response to the first transmission parameter. A system for implementing the method is also disclosed.

Abstract: A reliable and inexpensive method for deploying, operating and maintaining optical amplifiers in a variety of optical networks under a wide range of conditions using channel number reference tables. A preferred embodiment of the current invention may control one or more optical amplifiers or gain blocks operating in a variety of modes such as AGC mode, ALC mode and hybrid AGC/ALC mode without requiring the use of expensive channel counters. Channel number reference tables may be calculated based on initial input optical power output readings and a count of the number of channels initially served by the amplifier. According to the current invention, changes in the number of channels may be monitored and used to control a gain block by monitoring the gain block input optical power output, converting to a gain block voltage and referencing the channel number reference table.

Abstract: A Raman amplifier, system and method using a plurality of pumps configured to pump light into an optical fiber so as to Raman-amplify an optical signal propagating through the optical fiber. The Raman amplifier also includes an optical coupler configured to optically interconnect the pumping device with the optical fiber, and a control unit configured to control the pumping device so as to achieve a target amplification performance. Further, the control unit monitors the Raman-amplified WDM signal and determines if the monitored Raman-amplified WDM signal is within an allowable tolerance of the target amplification performance. If the Raman-amplified signal is not within the allowable tolerance, the control unit actively controls the pumps to bring the monitored Raman-amplified signal within the allowable tolerance of the target amplification profile.

Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.

Abstract: A multiplex optical communication system transmitting a multiplex optical signal between terminal equipments each including converters producing optical signals combined to the multiplex optical signal, through repeater equipment including an optical amplifier, under controlling the amplifier so that when a converter is added or removed, a time constant of the amplifier is equal to a time constant of the added or removed converter, or the amplifier produces output under constant output level control before adding or removing the converter and after the amplifier produces final output and constant gain control during the added or removed converter increases or decreases output. The time constant control is performed to the amplifier by making the amplifier repeat start and stop of increasing or decreasing output step by step in accordance with prescribed objective values corresponding to half way output of the optical amplifier.

Abstract: The invention includes a method for controlling amplifier output power in an optical communications network having channel add/drop capability. A first transmission parameter and a second transmission parameter are determined at a first amplifier. In an exemplary embodiment, the first transmission parameter is a composite express signal-to-noise ratio and the second transmission parameter is a composite signal-to-noise ratio. The total output power of a downstream amplifier is adjusted in response to the first transmission parameter and second transmission parameter. A system for implementing the method is also disclosed.

Abstract: An optical communication system according to the present invention includes an optical transmission device and a repeater. The repeater has an automatic level controller for performing average level constant control to an optical signal transmitted from the optical transmission device. The optical transmission device has an average level detector for detecting an average level detection signal of the optical signal transmitted to the repeater, and the average level detector transmits the average level detection signal to the repeater. When the automatic level controller of the repeater detects an average level detection signal, the automatic level controller performs average level constant control for the optical signal with reference to the average level detection signal.

Abstract: An optical amplifier includes an optical amplification medium which has simultaneous inputs of a WDM signal light and a pumping light and amplifies the WDM signal light, a pumping light source, and an amplification characteristic supervisor part which evaluates the gain tilt of amplified WDM signal lights. The supervisor part is provided in advance with a record of the relation between the medium output light power and the pumping light power corresponding to the output light power in terms of a number of proper curves plotted for certain gain tilts, and adapted to select a proper curve which is nearest to the relation in operation between the power of the pumping light which is incident to the medium in operation and the resulting amplified output light power from among the recorded proper curves, thereby determining the gain tilt of the medium based on the selected proper curve.

Abstract: The present invention aims at providing a controlling apparatus and a controlling method for a wavelength division multiplexing optical amplifier to reduce the controlling error due to the affection of noise light included in the monitoring light to be used for controlling the wavelength division multiplexing optical amplifier, to thereby realize precise controlling of the optical amplifier. To this end, the controlling apparatus for a wavelength division multiplexing optical amplifier according to the present invention: branches, by a photocoupler, a portion of WDM signal light amplified by a light level controlling part; and separates the thus branched light into groups of even-numbered channel components and odd-numbered channel components making use of a wavelength channel separate filter. Further, monitor signals corresponding to the light powers of the even-numbered group and odd-numbered group, respectively, are generated by respective photoelectric converting parts and LPF's.

Abstract: The amplification and noise level of an optical communication signal is controlled by providing a feedback loop to adjust the energy level of an optical pump energy source used to amplify the communication signal. The communication signal is combined with an optical control signal outputted by the pump energy source. The communication signal is amplified as the combined signals pass through an erbium doped fiber optic cable energized by the control signal. The amplified communication signal is then separated from the control signal. The control signal is in a depleted state (substantially residual pump energy) after traveling through the length of the erbium doped fiber optic cable. A feedback signal, used to adjust the energy level of the control signal, is generated based on the amplified communication signal and the depleted control signal.

Abstract: The present invention provides a wavelength division multiplex light communication system using an optical amplifier which can amplifying and translating a multiplex light signal obtained by wavelength division multiplexing a plurality of channel light signals and can perform its control such that when the number of channels n is the maximum number of channels nmax, the total light output power Pt is maximum, Pmax and such that when the number of channels n for light signals is smaller than nmax, the total light output power Pt obtained by amplifying said multiplex light signal is substantially Pt>Pmax×n/nmax.

Abstract: A variable attenuator is inserted into an optical input part and a feedback control is performed so that an optical input to an amplifying optical fiber becomes constant. Further, a control for changing a total optical output and an optical input to the amplifying optical fiber is performed on the basis of channel number information obtained from a supervisory signal. When light to/from an intermediate optical component is detected and the absence of the component is detected, pumping is suppressed, thereby avoiding occurrence of an optical surge at the time of connection of the optical component and a signal indicative of detachment of the optical component is generated.

Abstract: An optical fiber amplifier has a length of active optical fiber into which pump light from a pump laser is injected. The pump laser is locally controlled by a laser monitor diode, the pump laser and the laser monitor forming a pump laser module. The overall amplification of the amplifier is controlled by two control loops: a feed forward loop and a feed back loop. These two control loops also control the pump laser. The feed forward loop gives a fast response and receives an input signal from an input monitoring diode. The feed back loop gives a slower response and sets the overall gain of the amplifier. The feed back loop receives an input signal from an output monitoring diode. In the feed forward loop, the input power level is biased and controlled by a set offset values from sources to provide a signal corresponding to a pump power reference level which maintains the desired gain. The offsets of characteristic curves indicating an overall behavior of the optical amplifier.

Abstract: A light amplifying device, which employs a SOA, has been disclosed, wherein, the gain of the SOA is adjusted by the injection of light into the semiconductor optical amplifier. The signal light and the CW control light are combined, entered into the SOA, and the control light is removed from the light output from the SOA by the filter, the amplified signal light is divided by the divider, and the power of one of the divided lights is detected. The control unit changes the power of the control light in accordance with the detected power. The gain is adjusted by changing the power of the control light. In this structure, the density of the carrier in the active layer is reduced by increasing the power of the control light in order to decrease the gain, but the saturation light output power of the SOA is increased because the carrier life is reduced.

Abstract: A multi-wavelength light amplifier includes a first-stage light amplifier which has a first light amplifying optical fiber amplifying a light input, a second-stage light amplifier which has a second light amplifying optical fiber amplifying a first light output from the first-stage light amplifier, and an optical system which maintains a second light output of the second-stage light amplifier at a constant power level. The first-stage and second-stage light amplifiers have different gain vs wavelength characteristics so that the multi-wavelength light amplifier has no wavelength-dependence of a gain thereof.

Abstract: Regulated optical amplifiers for wavelength-division multiplex signal transmission that include a first control device for regulating the gain and a second, dominating control device having a significantly slower control behavior for regulating the output power level in conformity with a supplied rated power value. Both rapid level changes as well as slow changes in attenuation of the transmission path can be leveled with a transmission path utilizing these amplifiers.

Abstract: Systems and methods for determining the distributed gain properties of a fiber plant are disclosed. A detector, a controller and a memory device are utilized to measure signal levels while the pump power is increased. The controller calculates gain for various pump power levels to construct a gain profile or transfer function which may be, for example, gain as a function of pump power. A gain transfer function is constructed for the particular fiber plant to which optical pump is connected. The constructed gain transfer function relates the output power of the optical pump and the signal gain of the signal travelling in the fiber plant. A controller utilizes the constructed gain transfer function to control the output power of the optical pump to produce a desired amount of signal gain. The gain transfer function may be stored as a look-up table and accessed by the controller to determine the amount of output power corresponding to a desired gain level.