CN102243413A - Composite type double-channel continuous adjustable light delay - Google Patents

Abstract

The invention relates to a continuous adjustable light delay, in particular to a composite type double-channel continuous adjustable light delay, and solves the problem that the conventional light delay cannot have delay quantity and adjustable continuity simultaneously and can realize the ten-micro-second adjustable delay of a double-channel signal. A slowdown (to-be-delayed) signal, namely signal 1, in the double-channel signal enters a Brillouin optical fiber ring which consists of a first switch, an optical isolator, a polarization controller, a first optical fiber, a circulator and an attenuator and is subjected to Brillouin slowdown light delay and linear light transmission delay in the Brillouin optical fiber ring; the signal in the other channel, namely signal 2, enters a second optical fiber ring which consists of a second switch and a second optical fiber and is subjected to the linear light transmission delay in the second optical fiber ring; a delay quantity difference between the signal 1 and the signal 2 is relative delay of the two signals; and adjustment of the light delay is realized by controlling a time sequence of the first control switch and the second control switch and using the power of a pump light. The composite type double-channel continuous adjustable light delay is applicable to light cache, light storage, data synchronization and light signal processing.

Description

Composite dual-channel continuous dimming delayer

technical field

The invention relates to a continuously adjustable light delay device.

Background technique

The controllable optical delay device has important application prospects in optical buffering, optical storage, data synchronization and optical signal processing, and is one of the important components to realize all-optical laser communication. Whether it is continuously adjustable and the size of the delay range are two important parameters to measure the performance of the optical delayer. The current optical delayer cannot take into account these two aspects: that is, the delayer with adjustable delay function generally has a small adjustable delay range, and the delayer with a large adjustable delay range generally cannot achieve continuous adjustment.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing optical delayer cannot take into account both the delay amount and the adjustable continuity, thereby providing a composite dual-channel continuously adjustable optical delayer.

A composite dual-channel continuously adjustable optical delay device, which includes a Brillouin fiber ring and a second fiber ring, the Brillouin fiber ring is composed of a No. 1 control switch, an optical isolator, a polarization controller, a No. 1 optical fiber, Composed of circulator and attenuator; the second optical fiber ring is composed of No. 2 control switch and No. 2 optical fiber; the length of No. 1 optical fiber is twice that of No. 2 optical fiber;

The signal to be delayed is input to the optical isolator through the No. 1 output port of the No. 1 control switch. After being processed by the optical isolator, it is input to the polarization controller. After being processed by the polarization controller, it is injected into the No. 1 optical fiber. The pump light is injected into a No. 1 optical fiber, the pump light interacts with the signal to be delayed in No. 1 optical fiber to generate a slow light delay based on the Brillouin scattering effect. The delayed signal is input to the attenuator through the circulator and processed by the attenuator Then input to the No. 1 input terminal of the No. 1 control switch to complete a loop in the Brillouin fiber ring; after repeated N1 loops, output through the delayed signal output port of the No. 1 control switch;

The second signal is injected into the No. 2 optical fiber through the No. 1 output port of the No. 2 control switch, and then input to the No. 1 input port of the No. 2 control switch after being transmitted by the No. 2 optical fiber to complete a loop in the second fiber ring; repeat After N2 loops, it is output through the second signal output terminal of the No. 2 control switch;

Both N1 and N2 are positive integers.

In the Brillouin fiber ring, after the delayed signal is repeatedly looped N1 times, the total optical delay is Δt, and the maximum value Tmax of the optical delay is determined by the number of loops and the gain of each loop, where the gain of each loop is determined by the pump Pu power regulation.

The delay of the signal to be delayed relative to the second signal is:

${\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="N"\; filenames="HDA0000074645670000011.png,HDA0000074645670000012.png"\; state="\{\{state\}\}">N</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}$

where ΔT is the single-turn transit time caused by transmission in the Brillouin fiber ring, and the single-turn transit time in the second fiber ring is ΔT/2.

The invention takes into account the delay range of the continuously adjustable light delay amount, realizes continuous adjustment while the adjustable delay range is large, and can realize continuously controllable light delay of nanosecond to microsecond level.

Description of drawings

Fig. 1 is a structural representation of the present invention, and mark 11 is the signal input end to be delayed of No. 1 control switch; Mark 71 is the second road signal input end of No. 2 control switch; Fig. 2 is the amount of time delay described in the specific embodiment schematic diagram.

Detailed ways

Specific Embodiments 1. This embodiment is described in conjunction with FIG. 1. The composite dual-channel continuously adjustable optical delay device includes a Brillouin fiber ring and a second fiber ring, and the Brillouin fiber ring is controlled by No. 1. 1. Optical isolator 2, polarization controller 3, No. 1 optical fiber 4, circulator 5 and attenuator 6; the second optical fiber ring is composed of No. 2 control switch 7 and No. 2 optical fiber 8; the length of No. 1 optical fiber 4 is 2 times of No. 2 optical fiber 8;

The signal to be delayed (signal 1) is input to the optical isolator 2 through the No. 1 output terminal 13 of the No. 1 control switch 1. After being processed by the optical isolator 2, it is input to the polarization controller 3. After being processed by the polarization controller 3, it is injected into the No. 1 Optical fiber 4, the pumping light is injected into No. 1 optical fiber 4 through a circulator, and the pumping light interacts with the signal to be delayed in No. 1 optical fiber 4 to generate a slow light delay based on the Brillouin scattering effect, and the delayed The signal is input to the attenuator 6 through the circulator, and after being processed by the attenuator 6, it is input to the No. 1 input terminal 14 of the No. 1 control switch 1 to complete a loop in the Brillouin fiber ring; after repeated N1 loops, it passes through the No. 1 Controlling the output of the delayed signal output terminal 12 of the switch 1;

The second road signal (signal 2) is injected into the No. 2 optical fiber 8 through the No. 1 output port 73 of the No. 2 control switch 7, and is input to the No. 1 input port 74 of the No. 2 control switch 7 after the transmission of the No. 2 optical fiber 8, and completes the No. 1 input port 74 of the No. 2 control switch 7. A loop in the second optical fiber ring; after repeated N2 loops, output through the second signal output port 72 of the second control switch 2;

Both N1 and N2 are positive integers.

Embodiment 2. The difference between this embodiment and the composite dual-channel continuously adjustable optical delay device described in Embodiment 1 is that, in the Brillouin fiber ring, after the delayed signal is repeatedly looped N1 times, The total optical delay is Δt, and the maximum value Tmax of the optical delay is determined by the number of loops and the Brillouin gain of each circle, where the Brillouin gain of each circle is adjusted by the pump power.

Embodiment 3. The difference between this embodiment and the composite dual-channel continuously adjustable dimming delayer described in Embodiment 1 is that the delay of the signal to be delayed relative to the second signal is:

${\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="N"\; filenames="HDA0000074645670000011.png,HDA0000074645670000012.png"\; state="\{\{state\}\}">N</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}$

where ΔT is the single-turn transit time caused by transmission in the Brillouin fiber ring, and the single-turn transit time in the second fiber ring is ΔT/2.

Working principle: The Brillouin amplification effect has the effect of slowing down the speed of light, that is, the group velocity of the amplified signal light will decrease, and the slow light delay can be realized by adjusting the pump light power of the Brillouin effect. By adjusting the power of the pump light, the gain of the signal light can be adjusted, thereby adjusting the amount of light delay. Since the mapping optical delay from the pump light power to the slow light delay is continuous mapping, and the pump light power can be continuously adjusted, the Brillouin slow light delay can also be continuously adjusted.

The present invention is a composite slow light delay device based on a circular Brillouin amplification delay structure, which can obtain a continuously adjustable slow light delay from nanoseconds to microseconds. The present invention makes the signal to be delayed undergo Brillouin amplification The slow light delay caused by and the transit delay caused by transmission. The second signal only experiences the transit delay caused by the transmission in the second optical fiber 8 . The number of cycles of the signal to be delayed and the second signal in their respective rings is controlled by their respective switches, and the single-turn transit time caused by transmission in the Brillouin fiber ring is ΔT, then in the second fiber ring The lap time is ΔT/2. Assuming that in the Brillouin fiber ring, the total slow light delay introduced by the Brillouin amplification effect after N1 cycles is Δt, the maximum value is Tmax, and Tmax is determined by the number of cycles and the gain of each cycle. The gain of each circle can be adjusted by the pump power. After passing through this system, the delay of signal 1 relative to signal 2 is:

${\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="N"\; filenames="HDA0000074645670000011.png,HDA0000074645670000012.png"\; state="\{\{state\}\}">N</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}$

in:

N ₂ =0, 1, 2...2N1

Δt=[0, T _max ]

In addition to being controlled by the No. 1 control switch, the number of cycles of the signal to be delayed is also determined by the Brillouin gain and loss in the loop it bears. In actual work, in order to ensure that no self-excited SBS is generated in the ring, the Brillouin gain is smaller than the loss in the ring. This causes the signal to be delayed to cycle through the loop in a decayed state. By adjusting the pump light power in the Brillouin fiber ring, the loop loss is changed by adjusting the variable attenuator accordingly, so that the difference between the two remains unchanged, and the total number of cycles in the loop can be kept constant. , to achieve continuous adjustment of Δt between [0, Tmax]. For a given Δt, the delay amount ΔT _d can take the following values, as shown in Figure 2, namely: 0+Δt, ΔT/2+Δt, ΔT+Δt...N ₁ ΔT+Δt

It can be seen that if T _max ≥ ΔT/2, since Δt is continuously adjustable. By adjusting the No. 2 control switch to control the value of N ₂ , the value of ΔT _d can be changed continuously between 0 and N ₁ ΔT+Δt.

Embodiment 4. This embodiment adopts the structure of Embodiment 3, and the signal light has circled 31 times in the Brillouin fiber ring, wherein:

The no-pump transit time ΔT is:

ΔT=572ns

The slow light delay based on stimulated Brillouin scattering is:

Δt=468ns

Δt≥ΔT/2 is achieved, so T _max ≥ΔT/2.

The total delay is:

N ₁ ΔT+Δt＝31×572+468≈18μs

A continuously adjustable time delay from 0 to 18 microseconds is obtained. Its delay adjustment resolution can reach nanosecond level.

For any given delay time ΔT _d , the delay amount consists of two parts, one is the linear delay amount, and the other is the delay amount Δt introduced by the stimulated Brillouin scattering slow light effect. For a given ΔT _d , there are many combinations of N1 and N2. Selecting as few N1 and N2 as possible is beneficial to obtain a high signal-to-noise ratio, and the system has a small inherent delay. The selection method is:

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="N"\; filenames="HDA0000074645670000011.png"\; state="\{\{state\}\}">N</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; ceil</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="N"\; filenames="HDA0000074645670000011.png,HDA0000074645670000012.png"\; state="\{\{state\}\}">N</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}<span\; class="notranslate">\; ]</span>$

Among them, ceil[x] is the smallest integer greater than or equal to x, and [x] is the integer part of x. M is determined according to the relevant data measured by the specific Brillouin slow light delay ring. Specifically as follows, adjust the pump light to the maximum value when there is no self-excited SBS in the Brillouin ring. At this time, the number of rings of the signal light ring in the Brillouin ring is the largest. For example, when there are 31 rings, record the excited The amount of slow light delay caused by Brillouin scattering, the delay amount at this time is the maximum slow light delay amount obtained in each circle, starting from the slow light delay amount of the first circle, until the minimum number of circles M, Make the cumulative slow light delay from the 1st circle to the Mth circle greater than or equal to the Brillouin delay Δt in the given ΔT _d :

$\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}<span\; class="notranslate">\; ]</span>\frac{\mathrm{<span\; class="notranslate">\; \&Delta;<figure-callout\; id="2"\; label="T"\; filenames="HDA0000074645670000011.png,HDA0000074645670000012.png"\; state="\{\{state\}\}">T</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$

The value of M can be determined. This value represents the corresponding Brillouin delay amount that the signal light can reach after going through M cycles.

The determined N1 and N2 determine the amount of linear delay. By lowering the pump light, Δt can be adjusted to the value to be adjusted, thereby realizing the overall delay of ΔT _d .

Claims (3)

1. the continuous tunable optical chronotron of compound binary channels, it is characterized in that: it comprises the Brillouin fiber optic ring and second fiber optic loop, and described Brillouin fiber optic ring is made up of a gauge tap (1), optoisolator (2), Polarization Controller (3), an optical fiber (4), circulator (5) and attenuator (6); Second fiber optic loop is made up of No. two gauge tap (7) and No. two optical fiber (8); The length of an optical fiber (4) is 2 times of No. two optical fiber (8);

Treat that inhibit signal inputs to optoisolator (2) through an output terminal (13) of a gauge tap (1), after handling, optoisolator (2) inputs to Polarization Controller (3), after handling, injects Polarization Controller (3) optical fiber (4), pump light injects an optical fiber (4) by circulator (5), described pump light interacts with treating inhibit signal in an optical fiber (4), generation is based on the slower rays time-delay of Brillouin scattering effect, signal after the time-delay inputs to attenuator (6) through circulator (5), after attenuator (6) is handled, input to an input end (14) of a gauge tap (1), finish once going in ring in the Brillouin fiber optic ring; Carry out repeatedly going in ring for N1 time after the inhibit signal output terminal (12) for the treatment of of a gauge tap (1) is exported;

The second road signal injects No. two optical fiber (8) through an output terminal (73) of No. two gauge tap (7), inputs to an input end (74) of No. two gauge tap (7) after this No. two optical fiber (8) transmission, finishes once going in ring in second fiber optic loop; Carry out repeatedly going in ring for N2 time after the second road signal output part (72) output of No. two gauge tap (2);

Described N1 and N2 are positive integer.

2. the continuous tunable optical chronotron of compound binary channels according to claim 1, it is characterized in that in the Brillouin fiber optic ring, after treating that inhibit signal carries out going in ring for N1 time repeatedly, total light time-delay is Δ t, the maximum of T max of light time-delay is determined jointly by the circulation number of turns and each circle brillouin gain, wherein respectively encloses brillouin gain and regulated by pump power.

3. the continuous tunable optical chronotron of compound binary channels according to claim 1 is characterized in that treating that inhibit signal with respect to the time-delay of the second road signal is:

${\mathrm{\&Delta;T}}_d=(N_1-N_2\frac{1}{2})\mathrm{\&Delta;T}+\mathrm{\&Delta;t}$

Δ T is the individual pen transit time that is caused by transmission in the Brillouin fiber optic ring in the formula, and the individual pen transit time in second fiber optic loop is Δ T/2.

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