KR19980060352A - EDFA Gain Control - Google Patents

Abstract

The present invention detects the presence or absence of input optical power loss at an EDFA input terminal regardless of the number of input channels of a multi-channel WDM system and then compensates for the control delay until the input optical power loss is detected. An EDFA gain control device is provided.

The conventional EDFA gain control device saturates the gain of the channels that remain without disconnection, i.e., the control delay that occurs until a loss of the incoming optical power is detected and a compensation signal is compensated for the loss. There was a problem that there is a section to let.

In order to solve this problem, the present invention extracts a channel unit comprising first to n-th channels transmitting different wavelengths, an input unit for receiving and transmitting different wavelengths input from the channel unit, and a signal transmitted from the input unit. A photodiode for searching for an optical power loss, a laser diode for compensating optical power loss according to the optical power detected by the photodiode, a fiber delay unit for compensating for control delays caused by the photodiode and the laser diode; It is composed of EDFA which optically amplifies the transmitted wavelength by controlling delay compensation from the fiber delay unit according to the control signal transmitted from the laser diode and outputs and transmits a more uniform gain.

Description

EDFA Gain Control

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EDFA gain control apparatus. In particular, the present invention relates to an EDFA gain control apparatus, which detects input optical power loss at an EDFA input stage regardless of the number of input channels of a WDM system. This is to eliminate the control delay until the optical power loss is detected.

As shown in FIG. 1, a conventional Doped Fiber Optical Amplifier (EDFA) gain control device includes first to nth channels (1-1 to 1-n) for transmitting different wavelengths. A channel unit 1, an input unit 2 for receiving and transmitting different wavelengths input from the channel unit 1, an EDFA 3 for optically amplifying and outputting the wavelength transmitted from the input unit 2, A grape diode (4) for extracting the optically amplified signal from the EDFA (3) to search for optical power loss, and a laser diode for compensating optical power loss according to the optical power detected by the photodiode (4); It is composed of 5).

Referring to the operation of the conventional EDFA gain control device configured as described above is as follows.

First, the first through n-th channels 1-1 through 1-n in the channel unit 1 transmit different wavelengths.

Then, the input unit 2 receives and transmits different wavelengths input from the channel unit 1.

Accordingly, the EDFA 3 optically amplifies and outputs the wavelength transmitted from the input unit 2.

Then, the grape diode 4 extracts the optically amplified signal from the EDFA 3 to search for and transmit the optical power loss.

Here, the optical power loss means that some of the first to nth channels 1-1 to 1-n in the channel portion 1 are disconnected.

Accordingly, the laser diode 5 transmits a signal for compensating optical power loss according to the optical power detected by the photodiode 4.

Then, the EDFA 3 keeps the input optical power constant according to the compensation signal output from the laser diode 5, thereby providing the first to nth channels 1-1 to 1-n in the channel section 1. The party benefits will be kept constant.

However, such a conventional EDFA gain control device detects the loss of the input optical power and gains the control delay that occurs until a compensation signal is transmitted to compensate for the loss, that is, the gain of the channels in which the signal is not disconnected. There was a problem that there is a section to saturate.

Therefore, the present invention controls whether the input optical power loss is detected after detecting the input optical power loss at the EDFA input terminal regardless of the number of input channels of the WDM system. Its purpose is to provide an EDFA gain control device with no delay.

1 is a configuration diagram of a conventional EDFA gain control device.

2 is a configuration diagram of an EDFA gain control apparatus according to the present invention.

Explanation of symbols for the main parts of the drawings

101: channel portions 101-1 to 101-n: first to nth channels

102 input unit 103: captive diode

104: laser diode 105: fiber delay unit

106: EDFA

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an EDFA gain control apparatus according to the present invention, and includes a channel unit 101 including first to nth channels 101-1 to 101-n transmitting different wavelengths. And an input unit 102 for receiving and transmitting different wavelengths input from the channel unit 101, a grape diode 103 for extracting a signal transmitted from the input unit 102, and searching for an optical power loss. And a laser diode 104 for compensating optical power loss according to the optical power detected by the photodiode 103, and a fiber for compensating control delay caused by the photodiode 103 and the laser diode 104. EDFA (1) for optically amplifying a wavelength transmitted by control delay compensation from the fiber delay unit 105 according to the control signal transmitted from the delay unit 105 and the laser diode 104, and outputting and transmitting a more constant gain. 06).

Referring to the operation and effect of the present invention configured as described above are as follows.

First, the first to nth channels 101-1 to 101-n in the channel unit 101 transmit different wavelengths.

Then, the input unit 102 receives and transmits different wavelengths input from the channel unit 101.

Accordingly, the grape diode 103 extracts the signal transmitted from the input unit 102 to search for and output the optical power loss.

Then, the laser diode 104 transmits a control signal for compensating optical power loss according to the optical power detected by the photodiode 103.

In addition, the fiber delay unit 105 compensates for the control delay caused by the photodiode 103 and the laser diode 104 to transmit.

Here, the fiber delay unit 105 has a predetermined length in consideration of the control delay time.

Accordingly, the EDFA 106 optically amplifies the wavelength transmitted by the control delay compensation from the fiber delay unit 105 according to the control signal transmitted from the laser diode 104 to output and transmit a more constant gain.

As described above, the present invention compensates for the input optical power loss after detecting the presence or absence of the input optical power loss at the EDFA input terminal regardless of the number of input channels of the WDM system. By eliminating the control delay until it is possible to achieve a more stable gain control.

Claims (1)

A channel unit 101 including first to nth channels 101-1 to 101-n transmitting different wavelengths, and an input unit 102 receiving and transmitting different wavelengths input from the channel unit 101. ), A grape diode 103 for extracting a signal transmitted from the input unit 102 to search for optical power loss, and a laser diode for compensating optical power loss according to the optical power detected by the photodiode 103. (104), a fiber delay unit (105) for compensating control delays caused by the photodiode (103) and the laser diode (104), and the fiber in accordance with a control signal transmitted from the laser diode (104). EDFA gain control field comprising an EDFA 106 which optically amplifies the transmitted wavelength by the control delay compensation from the delay unit 105 and outputs and transmits a more constant gain. Chi.