KR0178453B1 - Multistep optical fiber loop mirror - Google Patents

Abstract

The present invention discloses a multi-stage optical fiber loop mirror capable of generating optical pulses in units of 3 ^N bits, which is a new structure of a series-connected pulse generator, and capable of generating optical pulses more simply and effectively than conventional methods.

Description

Multi-stage Fiber Optic Loop Mirror

Figure 1a is a schematic diagram of a conventional pulse generator pulse generator.

1B and 1C are input / output waveform diagrams for explaining FIG. 1A.

2a is a structural diagram of a conventional pulse generator.

2B and 2C are input and output waveform diagrams for explaining FIG. 2A.

3a is a structural diagram of an optical clock triplex multiplier using a two-stage optical fiber loop mirror proposed in the present invention.

FIG. 3B is an equivalent configuration diagram of FIG. 3A. FIG.

4A and 4B are input and output waveform diagrams for explaining FIG. 3A.

5 is a structural diagram of an optical clock 3 ^N multiplier using a multi-stage optical fiber loop mirror proposed in the present invention.

* Explanation of symbols for main parts of the drawings

100, 100-1 to 100-6: optical coupler 200: optical polarization regulator

300,300-1 to 300-4: optical fiber delay line

The present invention relates to a multi-stage optical fiber loop mirror, and more particularly, to a multi-stage optical fiber loop mirror capable of increasing the frequency of the optical clock by 3 ^N bits.

In general, an optical pulse generator using a multi-stage optical fiber loop mirror is used in various ways such as a frequency divider that increases a pulse rate, a pulse bit-rate compressor, and a cell multiplexer. Optical pulse generators are usually divided into three methods: serial, parallel, and series-parallel mixing. The serial method has good light efficiency but generates light pulses only in units of 2 ^N bits. On the other hand, the parallel method can generate an arbitrary number and light pulses, but the light efficiency is very low. Therefore, it is used to take advantage of each method by properly mixing the parallel and series method.

Figure 1a is a structural diagram of a conventional pulse generator pulse generator.

Assume that one pulse is input to the input terminal. This one pulse is divided into equal powers by the first optical coupler 100-1, and the pulse at terminal 1 is further divided into terminals 3 and 4 by the same power by the second optical coupler 100-2. Likewise, the pulse at terminal 2 is again divided into terminals 5 and 6 by third optical coupler 100-3. The pulse at the terminal 3 goes to the terminal 7 through the first optical fiber delay line 300-1, the pulse at the terminal 4 goes to the terminal 8 through the second optical fiber delay line 300-2, and at the terminal 5. The pulses of P are advanced to the terminal 9 through the third optical fiber delay line 300-3, and the pulses of the terminal 6 are advanced to the terminal 10 through the fourth optical fiber delay line 300-4. In this case, since the periods of the first to fourth optical fiber delay lines are all different, the pulses proceeding to the terminals 7 to 10 proceed with different parallaxes. The pulses at the terminals 7 and 8 are synthesized into pulses having different parallaxes by the fourth optical coupler 100-4 and proceed to terminal 11. Similarly, the pulses at the terminals 9 and 10 are synthesized into pulses having different parallaxes by the fifth optical coupler 100-5 and proceed to terminal 12. The pulses at the terminals 11 and 12 are synthesized into pulses having different parallaxes by the sixth optical coupler 100-6, and outputted to the output terminal. The input and output signal characteristics of such a pulse generator are as shown in Figs. 1b and 1c.

2A is a structural diagram of a conventional pulse generator.

Assume that one pulse is input to the input terminal. This one pulse is divided into equal powers by the first optical coupler 100-1, and the pulse at terminal 1 is advanced back to terminal 4 by the same power by the second optical coupler 100-2. The pulse at terminal 2 proceeds to terminal 3 via the first optical fiber delay line 300-1, and the pulse at terminal 3 is again divided into terminal 5 with the same power by the second optical coupler 100-2. The pulse at terminal 5 proceeds to terminal 6 via second optical delay line 300-2. The pulses at the terminals 4 and 6 are synthesized into pulses having different parallaxes by the third optical coupler 100-3, and outputted to the output terminals. The input / output signal characteristics of the pulse generator are shown in FIGS. As shown.

An object of the present invention is to provide a multi-stage optical fiber loop mirror that can generate optical pulses in units of 3 ^N bits, which is a new structure of a series-connected pulse generator, and can generate optical pulses more simply and effectively than conventional methods.

In the multi-stage optical fiber loop mirror according to the present invention for the purpose of the above-mentioned object, N optical fiber loop mirrors are connected in series using the optical fiber loop mirror to which the bit signal is input, and the optical fiber delay line of each optical fiber loop mirror. The number is characterized by the following equation.

KN = N-1

Where K _N : number of optical fiber delay lines of the Nth optical fiber loop mirror

N: Nth fiber loop mirror

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

3a is a structural diagram of an optical clock triplex multiplier using a two-stage optical fiber loop mirror proposed in the present invention. It consists of two optical couplers 100, an optical polarization controller 200, and one optical fiber delay line 300. This can be thought of as a system having a transfer function H as shown in FIG. 3b.

In Figure 3a, when the signal '1' is input to terminal 1, the signals output to terminals 1 and 2 are H ₁₁ and H ₁₂ , and the signal 1 is input when the signal '1' is input to terminal 2 The signals output from terminals 2 and 2 are H ₂₁ and H ₂₂ , which are obtained by following equation (4).

On the other hand, the impulse response when using terminal 1 as input and terminal 2 as output becomes H ₁₂ . As shown in (Equation 2), three pulses of the same magnitude can be obtained by properly adjusting the values of θ and ψ. The characteristics of the input and output signals of the optical clock 3-bit multiplier are shown in Figs. 4A and 4B.

When the original clock frequency is f, the time delay T caused by the optical fiber delay line in the optical clock triplex is given by Equation 5 below.

5 is a structural diagram of an optical clock 3 ^N multiplier using a multi-stage optical fiber loop mirror proposed in the present invention.

N optical fiber loop mirrors (N to 1) are connected in series using an optical fiber loop mirror into which a bit signal is inputted as an N-stage optical fiber loop mirror. The number of optical fiber delay lines of each optical fiber loop mirror is determined by the following equation.

K _N = N-1

Where K _N : number of optical fiber delay lines of the Nth optical fiber loop mirror

N: Nth fiber loop mirror

Similarly, can be made to come out the clock pulses of the same size in the optical clock multiplier of the fifth degree 3 ^N bits by controlling the respective light polarization controller, wherein a delay time T is the same as the following (Formula 6).

As described above, according to the present invention, an optical pulse can be generated in units of 3 ^N bits, and a simpler and more effective optical pulse generator can be realized than the conventional method.

Claims (1)

N optical fiber loop mirrors in which the bit signal is input are N-stage optical fiber loop mirrors, and N optical fiber loop mirrors are connected in series, and the number of optical fiber delay lines of each optical fiber loop mirror is determined by the following equation. . K _N = N-1 Where K _N : number of optical fiber delay lines of the Nth optical fiber loop mirror N: Nth fiber loop mirror