JPS63107322A - Optical burst mode time division transmitter - Google Patents

Abstract

PURPOSE:To extend the transmission range without decreasing the photodetecting sensitivity by making the self-stimulated wavelength of a photoelectric converting element equal to that of an opposite photoelectric converting element in an optical burst mode time division transmitter having a photoelectric converting element converting light into electricity and vice versa. CONSTITUTION:An optical signal sent from an optical fiber 20 is received by an LED 1, received by a reception section 9, demultiplexed into a data and a wavelength data by a demultiplexing circuit 4, the wavelength data is received by a wavelength data reception circuit 5 and inputted to a stimulated wavelength control circuit comprising a temperature data generating circuit 14, a digital/analog converter 15, an error detection circuit 16, a temperature control circuit 17, a heater 18 and a sensor 11. The stimulated wavelength control circuit controls the wavelength of the LED 1 so as to be matched with the wavelength of the set wavelength data. In using the titled device for the master station side, since it is not required to control the wavelength of the LED 1, a selection circuit 10 is provided to select the device not applying the said control. Moreover, the master station side is provided with a wavelength monitor circuit 2 monitoring the self-stimulated wavelength and a multiplexer circuit 3 multiplexing the wavelength data to be monitored.

Description

Detailed Description of the Invention [Summary] In an optical burst mode time division transmission device (optical ping-pong transmission device) having one photoelectric conversion element that converts light to electricity and electricity to light, By making the self-emission wavelength the same as the self-emission wavelength of the other optoelectric conversion element, the transmission distance can be increased without reducing the light receiving sensitivity.

[Industrial application field]

The present invention relates to an improvement in an optical burst mode time division transmission device having a single photoelectric conversion element that converts light to electricity and electricity to light.

In the optical burst mode time division transmission device, it is desirable that the light receiving sensitivity does not decrease.

Note that the light receiving sensitivity of a photoelectric conversion element such as a light emitting diode (hereinafter referred to as LED) or a laser diode is as shown in FIG. It is known that when it is shortened to λ2, the photoelectric conversion efficiency is poor and the light receiving sensitivity is reduced.

[Conventional technology]

A conventional example will be explained below using figures.

FIG. 6 is a block diagram of the main parts of a conventional optical burst mode time division transmission system.

When the burst transmission data SDI is input manually in the optical burst mode time division transmission device on the master side shown in (A), the LEDI is driven in the drive circuit 3 to become an optical signal, which passes through the optical fiber 20 and is transmitted as shown in (B). The received data RD2 is sent to the optical burst mode time division transmission device on the slave side, is received by the LEDI', is electrically converted, and is transmitted through the receiving section 9° to the received data RD2.
received as.

Furthermore, when the burst transmission data SD2 is input to the optical burst mode time division transmission device on the slave side shown in (B),
The drive circuit 8' drives the LED 1' to generate an optical signal, which passes through the optical fiber 20 and is sent to the optical burst mode time division transmission device on the master side shown in (A), where it is received by the LED 1 and electrically converted. Through the receiving section 9, the received data RDI
received as.

The transmission from the master side and the transmission from the slave side are
As shown in (C), data is received from the master side and transmitted in a time-sharing manner after the guard time has elapsed.

In this way, communication is performed by performing so-called ping-pong transmission using one optical fiber 20.

[Problem that the invention seeks to solve]

However, the master side 0LEDI and the slave side 0LE
The emission wavelength of DI' does not necessarily match.

For example, if the emission wavelength of the slave side LEDI' is shorter than the emission wavelength of the master side LEDI, the slave side LED
As shown in FIG. 7, I' has a problem in that the light receiving sensitivity decreases and the transmission distance becomes short.

[Means for solving problems]

The above problem can be solved as shown in the principle block diagram (A) in FIG. , on the receiving side, a separation circuit 4 that separates wavelength data from received data, a wavelength data reception circuit 5 that receives the separated wavelength data, and a self-emission wavelength controlled based on the received wavelength data to be equal to the received wavelength. When the self-emission wavelength control circuit 6 is used to control the self-emission wavelength and the selection circuit 7 is used to select whether or not to control the self-emission wavelength, or when used as a master side, as shown in (B),
On the transmitting side, there is a wavelength monitor circuit 2 that monitors the self-emission wavelength and a multiplexer circuit 3 that multiplexes this monitored wavelength data.
When used as a slave side, as shown in (C), a separation circuit 4 is provided on the receiving side to separate wavelength data from received data.
and a wavelength data receiving circuit 5 that receives the separated wavelength data, and an emission wavelength control circuit 6 that controls the self-emission wavelength to be equal to the received wavelength based on the received wavelength data. The solution is an optical burst mode time division transmission device.

C action] When the selection circuit 7 in FIG. 1(A) is on the slave side, it selects the one that controls the self-emission wavelength, and when it is on the master side, it selects the one that does not control the self-emission wavelength. Therefore, according to the present invention, even if the optical burst mode time division transmission device shown in (A) is used on the master side and the slave side, (B
Even if the optical burst mode time division transmission device shown in (C) is used on the master side and the optical burst mode time division transmission device shown in (C) is used on the slave side, the wavelength of the photoelectric conversion element on the slave side will not be transmitted. Since the emission wavelength control circuit 6 controls the wavelength of the photoelectric conversion element on the master side to be equal to that of the photoelectric conversion element on the master side, the emission wavelength of the photoelectric conversion element on the master side and the slave side becomes equal, and the light receiving sensitivity decreases. This will prevent the transmission distance from becoming shorter.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a block diagram of a main part of an optical burst mode time division transmission apparatus according to an embodiment of the present invention, and FIG. 3 is a diagram showing a frame format in the case of FIG. 2.

Figure 2 shows an optical burst mode time division transmission device that can be used on either the master or slave side.
In addition, there are methods to control the emission wavelength of LEDI, such as changing the ambient temperature and changing the bias current. Figure 2 shows an example of controlling the emission wavelength by changing the ambient temperature. There is.

In Fig. 2, the temperature of the constant temperature bath 10 for LEDl is measured by the sensor 1.
1, the analog/digital converter 12 converts the signal into a digital signal, and the wavelength data creation circuit 13 generates the signal.
Wavelength data converted from this temperature is created and multiplexed with burst data in the multiplexing circuit 3, resulting in a frame format signal consisting of the frame pattern, wavelength data, and data shown in FIG. The LEDI is driven and an optical signal is transmitted through the optical fiber 20.

The optical signal sent from the optical fiber 20 is received by the LED 1, received by the receiver 9, separated into data and wavelength data by the separation circuit 4, and the wavelength data is received by the wavelength data receiver circuit 5. , the temperature data creation circuit 14 creates data on what temperature should be set to match this wavelength data with the wavelength of the LED 1 in the constant temperature oven 10, and sends it to the digital-to-analog converter 15. is converted into an analog value and sent to the error detection circuit 16.

The analog temperature value from the sensor 11 is input to the error detection circuit 16, the error between this value and the output of the digital-to-analog converter 15 is detected, and the error is reduced to O via the temperature control circuit 17. The current flowing through the heater 18 is controlled so that the wavelength of the LEDI matches the wavelength of the transmitted wavelength data.

Therefore, since the wavelength of LEDl matches the wavelength of the LED on the other side, the receiving sensitivity does not decrease and the transmission distance does not become short.

However, when this optical burst mode time-division transmission device is used on the master side, there is no need to control the wavelength of the LEDI, so a selection circuit 10 is provided to select the one not to perform this control.

Note that the temperature data creation circuit 14. Digital to analog converter 15. Error detection circuit 16. Temperature control circuit 17. Heater 18. The sensor 11 constitutes the emission wavelength control circuit 6 shown in FIG. 1, and the sensor 11 and the analog/digital converter 12. Wavelength monitor circuit 2 in wavelength data creation circuit 13
It consists of

Next, Figure 4 shows the configuration of an optical burst mode time division transmission device when used only on the master side and slave side.
This will be explained using FIG.

FIG. 4 is a block diagram of the main parts of the optical burst mode time division transmission device on the master side according to the embodiment of the present invention, and FIG. 5 shows the main parts of the optical burst mode time division transmission device on the slave side according to the embodiment of the present invention. FIG.

In order not to reduce reception sensitivity or shorten transmission distance,
All you have to do is send the wavelength data of the LED from the master side and make the wavelength of the LED on the slave side match the wavelength of the LED on the master side, so the master side multiplexes the wavelength data of LED1 with the burst data. Although it is necessary to transmit, there is no need to control the wavelength of LED1, so as shown in FIG. 4, multiplexing circuit 3. of FIG. 2 is used. Sensor 11. Analog-to-digital converter 12. Wavelength data creation circuit 13
is provided on the transmitting side, and the slave side controls the wavelength of LEDI' to match the wavelength of LED1 on the master side (although it is not allowed to transmit the wavelength of LED1', the fifth As shown in the figure, on the receiving side, as shown in FIG. .Sensor 11
All you have to do is prepare for it.

The operation of each part is the same as that explained in Fig. 2, and L E
Since the wavelengths of D 1 and LEDI' are the same, the reception sensitivity does not decrease and the transmission distance does not become short.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the wavelength of the LED is the same as that of the other party, so the reception sensitivity is not reduced.
This has the effect of not shortening the transmission distance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the principle of the present invention. FIG. 2 is a block diagram of the main parts of an optical burst mode time division transmission apparatus according to an embodiment of the present invention. FIG. 3 is a diagram showing the frame format in the case of FIG. , FIG. 4 is a block diagram of the main parts of the optical burst mode time division transmission device on the master side according to the embodiment of the present invention, and FIG. 5 is a block diagram of the main part of the optical burst mode time division transmission device on the slave side according to the embodiment of the present invention. Figure 6 is a block diagram of the main parts of a conventional optical burst mode time division transmission system, and Figure 7 shows the light receiving sensitivity when the light emitting wavelength of the light receiving LED is changed with respect to the light receiving wavelength λ1. FIG. In the figure, 1.1" is a photoelectric conversion element 2 light emitting diode, 2 is a wavelength monitor circuit, 3 is a multiplexing circuit, 4 is a separation circuit, 5 is a wavelength data receiving circuit, 6 is an emission wavelength control circuit, and 7 is a selection circuit. circuit, 8.8' is a drive circuit, 9.9' is a receiver, 10.10' is a constant temperature chamber, 11.11' is a sensor, 12 is an analog-to-digital converter, 13 is a wavelength data creation circuit, 14 is a Temperature data creation circuit, 15 is a digital-to-analog converter, 16 is an error detection circuit, 17 is a temperature control circuit, 7)

Claims (1)

[Claims] 1.) In an optical burst mode time-division transmission device having one photoelectric conversion element (1) that converts light to electricity and electricity to light, the transmitting side monitors the self-emission wavelength. Wavelength monitor circuit (2)
) and a multiplexing circuit (3) for multiplexing this monitored wavelength data, and the receiving side is equipped with a demultiplexing circuit (4) for demultiplexing the wavelength data from the received data and a wavelength data receiving circuit (4) for receiving the demultiplexed wavelength data. 5), an emission wavelength control circuit (6) that controls the self-emission wavelength to be equal to the received wavelength based on the received wavelength data, and a selection circuit (7) that selects whether or not to control the self-emission wavelength. ) An optical burst mode time division transmission device characterized by comprising: 2.) In an optical burst mode time division transmission device having one photoelectric conversion element (1) that converts light to electricity and electricity to light, when used as a master side, the self-emission wavelength is set on the transmitting side. It is equipped with a wavelength monitor circuit (2) that monitors wavelength data and a multiplexing circuit (3) that multiplexes this monitored wavelength data. When used as a slave side, a separation circuit ( 4) and a wavelength data receiving circuit (5) that receives the separated wavelength data, and an emission wavelength control circuit (6) that controls the self-emission wavelength to be equal to the received wavelength based on the received wavelength data.
What is claimed is: 1. An optical burst mode time division transmission device comprising: