Disclosure of Invention
Based on the defects, the invention provides the optical pulse delayer capable of automatically adjusting the working wavelength, which overcomes the problems of large volume, complex structure, fixed working wavelength and the like of the existing optical pulse delayer, and particularly overcomes the problem of pulse deformation caused by different transmittances of light waves with different wavelengths.
The purpose of the invention is realized as follows: an optical pulse delayer capable of self-adjusting working wavelength comprises a first coupler, a first photoelectric detector, a second coupler, a first isolator, a second photoelectric detector, a pumping light source, a piezoelectric ceramic piece, a gain annular waveguide, a third coupler, a second isolator and an analysis and control system, wherein the optical input end of the first coupler is the optical input end of the optical pulse delayer, the first optical output end of the first coupler is connected with the optical input end of the first photoelectric detector, the second optical output end of the first coupler is connected with the optical input end of the second coupler, the optical output end of the second coupler is connected with the optical output end of the first isolator, the optical input end of the first isolator is connected with the optical input end of the second photoelectric detector, the gain annular waveguide is respectively connected with the first optical input and output ends of the second coupler, the first optical input and output ends of the third coupler and the second optical input and output ends of the third coupler, one part of the gain annular waveguide is fixedly connected with the piezoelectric ceramic piece, the optical output end of the pumping light source is connected with the optical input end of a third coupler, the optical output end of the third coupler is connected with the optical output end of a second isolator, and the optical input end of the second isolator is the optical output end of the optical pulse delayer; the electrical output end of the first photoelectric detector is connected with the first electrical input end of the analysis and control system, the electrical output end of the second photoelectric detector is connected with the second electrical input end of the analysis and control system, the first electrical output end of the analysis and control system is connected with the electrical input end of the pumping light source, and the second electrical output end of the analysis and control system is connected with the electrical input end of the piezoelectric ceramic piece;
the second coupler, the gain annular waveguide and the third coupler form an annular resonant cavity, and the resonant wavelength of the annular resonant cavity is the working wavelength of the optical pulse delayer; when the optical pulse signal resonates in the ring resonant cavity, the ring resonant cavity can delay the optical pulse signal, and the delay is determined by the coupling ratio of the second coupler and the coupling ratio of the third coupler;
the wavelength of output light of the pump light source, the working wavelength of the first isolator and the working wavelength of the second isolator are the same, but different from the working wavelength of the optical pulse delayer;
the pump light source outputs pump light, the power of the pump light output by the pump light source is adjusted by changing the voltage of the electrical input end of the pump light source, and the pump light output by the pump light source can pump the gain annular waveguide;
the gain annular waveguide provides gain for the optical pulse delayer, namely, when the light with the wavelength of the working wavelength of the optical pulse delayer passes through the pumped gain annular waveguide, the gain is obtained;
the length of the piezoelectric ceramic piece can be adjusted by changing the voltage of the electric input end of the piezoelectric ceramic piece, so that the length of the gain annular waveguide and the cavity length of the annular resonant cavity are adjusted;
the first isolator and the second isolator only have a one-way conduction effect on light with the same wavelength as the working wavelength of the first isolator and have a two-way conduction effect on light with other wavelengths; the first coupler is a 1 multiplied by 2 coupler, the coupling ratio of the first coupler is far greater than 1, and the light intensity entering the second coupler through the first coupler is far greater than the light intensity entering the first photoelectric detector through the first coupler; the second coupler and the third coupler are both 2 × 2 couplers; the parameters of the first photoelectric detector and the second photoelectric detector are completely the same, and the working wavelengths of the first photoelectric detector and the second photoelectric detector are the working wavelengths of the optical pulse delayer;
the central wavelength of the optical pulse signal input into the optical pulse delayer needs to be simultaneously far away from the working wavelength of the first isolator and the working wavelength of the second isolator, so that the first isolator and the second isolator do not have a one-way conduction effect on the optical pulse signal input into the optical pulse delayer and have a two-way conduction effect; the optical pulse signal input into the optical pulse delayer needs to contain a trigger optical pulse, the pulse width of the trigger optical pulse needs to be larger than the response time of the analysis and control system, and the trigger optical pulse is positioned at the forefront end of the optical pulse signal;
the optical pulse signal input into the optical pulse delayer is input from the optical input end of the first coupler and is divided into two beams after passing through the first coupler, and because the coupling ratio of the first coupler is far greater than 1, and the light intensity entering the second coupler through the first coupler is far greater than the light intensity entering the first photoelectric detector through the first coupler, one beam with smaller light intensity enters the first photoelectric detector, and the other beam with larger light intensity enters the annular resonant cavity through the second coupler; because the first isolator has a bidirectional conduction effect on the optical pulse signal input into the optical pulse delayer, the optical pulse signal in the annular resonant cavity can be output by the second coupler and enter the second photoelectric detector through the first isolator, and meanwhile, because the second isolator has a bidirectional conduction effect on the optical pulse signal input into the optical pulse delayer, the optical pulse signal in the annular resonant cavity can also be output by the third coupler and output by the optical output end of the optical pulse delayer through the second isolator;
the first photoelectric detector converts the light intensity of a reference light signal into a reference voltage signal, and inputs the reference voltage signal into the analysis and control system, the analysis and control system generates a triangular wave voltage signal after receiving the reference voltage signal, and loads the triangular wave voltage signal to the electric input end of the piezoelectric ceramic piece so as to continuously change the length of the piezoelectric ceramic piece, further continuously change the length of the gain annular waveguide, and continuously change the cavity length of the annular resonant cavity, and the continuous change of the cavity length of the annular resonant cavity enables the resonant wavelength of the annular resonant cavity to continuously change; the cavity length of the annular resonant cavity is continuously changed, a transmission spectrum of trigger light pulse passing through the annular resonant cavity is obtained at the light output end of the second coupler, the light signal of the trigger light pulse passing through the annular resonant cavity and output by the second coupler is used as a transmission light signal, the transmission light signal is output by the second coupler and enters the first isolator, and the first isolator has a bidirectional conduction effect on the light pulse signal input into the light pulse delayer, so that the transmission light signal enters the second photoelectric detector through the first isolator, the second photoelectric detector converts the light intensity of the transmission light signal into a transmission voltage signal, and the transmission voltage signal is input into the analysis and control system;
in the analysis and control system, comparing a triangular wave voltage signal with a transmission voltage signal on the same time axis to obtain a voltage value x of the triangular wave voltage signal corresponding to the moment of the minimum voltage value of the transmission voltage signal, then generating a direct current voltage signal with the amplitude of x by the analysis and control system, taking the direct current voltage signal as a resonant direct current voltage signal, and loading the resonant direct current voltage signal to an electric input end of a piezoelectric ceramic piece to adjust the cavity length of an annular resonant cavity so as to adjust the resonant wavelength of the annular resonant cavity, namely the working wavelength of an optical pulse delayer, so that an optical pulse after triggering the optical pulse in the optical pulse signal input into the optical pulse delayer resonates in the annular resonant cavity to generate time delay;
meanwhile, in the analysis and control system, the loss of the trigger optical pulse in the ring-shaped resonant cavity is obtained from the minimum voltage value of the transmission voltage signal, then the analysis and control system generates a direct current voltage signal with the amplitude of y, the direct current voltage signal is used as a pumping direct current voltage signal, and the pumping direct current voltage signal is loaded to the electrical input end of the pumping light source so as to adjust the power of the pumping light output by the pumping light source, so that the pumping gain ring waveguide provides gain for the optical pulse signal input into the optical pulse delayer, and the gain of the optical pulse after the trigger optical pulse in the optical pulse signal input into the optical pulse delayer is equal to the loss in the ring-shaped resonant cavity.
The invention also has the following technical characteristics:
1. the analysis and control system comprises a sampling circuit, a comparison circuit, a first output circuit and a second output circuit; the first electrical input end of the sampling circuit is the first electrical input end of the analysis and control system, the second electrical input end of the sampling circuit is the second electrical input end of the analysis and control system, the electrical output end of the first output circuit is the first electrical output end of the analysis and control system, and the electrical output end of the second output circuit is the second electrical output end of the analysis and control system; the electrical output end of the first photoelectric detector is connected with the first electrical input end of the sampling circuit, the electrical output end of the second photoelectric detector is connected with the second electrical input end of the sampling circuit, the first electrical output end of the sampling circuit is connected with the first electrical input end of the comparison circuit, the second electrical output end of the sampling circuit is connected with the second electrical input end of the comparison circuit, the first electrical output end of the comparison circuit is connected with the electrical input end of the first output circuit, the electrical output end of the first output circuit is connected with the electrical input end of the pump light source, meanwhile, the second electrical output end of the comparison circuit is connected with the electrical input end of the second output circuit, and the electrical output end of the second output circuit is connected with the third electrical input end of the comparison circuit and the electrical input end of the piezoelectric; the electric output end of the first output circuit outputs a voltage signal which is loaded to the electric input end of the pumping light source so as to adjust the power of the pumping light output by the pumping light source; and the electric output end of the second output circuit outputs a voltage signal which is loaded to the electric input end of the piezoelectric ceramic piece so as to adjust the length of the piezoelectric ceramic piece and further adjust the length of the gain annular waveguide and the cavity length of the annular resonant cavity.
2. The pump light output by the pump light source enters the annular resonant cavity through the third coupler, the pump light in the annular resonant cavity can enter the first isolator through the second coupler, the wavelength of the output light of the pump light source is the same as the working wavelength of the first isolator, the first isolator has a one-way conduction effect on the light with the same wavelength as the working wavelength, the pump light cannot pass through the first isolator, meanwhile, the pump light in the annular resonant cavity enters the second isolator through the third coupler, the wavelength of the output light of the pump light source is the same as the working wavelength of the second isolator, the second isolator has a one-way conduction effect on the light with the same wavelength as the working wavelength, and the pump light cannot pass through the second isolator and is output by the light output end of the optical pulse delay unit.
3. The trigger light pulse is used for adjusting the working wavelength of the light pulse delayer and the power of the pump light output by the pump light source.
The invention has the advantages that: the invention has small volume and simple structure, can automatically adjust the working wavelength, has the same transmissivity to different wavelength components in the input optical pulse signal, and eliminates the pulse deformation caused by different transmissivity of the different wavelength components in the optical pulse signal.
Detailed Description
The invention is further illustrated by way of example in the accompanying drawings of the specification:
example 1
As shown in fig. 1-2, an optical pulse delayer for self-adjusting operating wavelength comprises a first coupler 1, a first photodetector 2, a second coupler 3, a first isolator 4, a second photodetector 5, a pumping light source 6, a piezoelectric ceramic plate 7, a gain ring waveguide 8, a third coupler 9, a second isolator 10 and an analysis and control system 11;
the optical input end of the first coupler 1 is the optical input end of the optical pulse delayer, the first optical output end of the first coupler 1 is connected with the optical input end of the first photoelectric detector 2, the second optical output end of the first coupler 1 is connected with the optical input end of the second coupler 3, the optical output end of the second coupler 3 is connected with the optical output end of the first isolator 4, the optical input end of the first isolator 4 is connected with the optical input end of the second photoelectric detector 5, the gain annular waveguide 8 is connected with the first optical input and output end and the second optical input and output end of the second coupler 3, the first optical input and output end and the second optical input and output end of the third coupler 9, a part of the gain annular waveguide 8 is fixed on the piezoelectric ceramic plate 7, the optical output end of the pump light source 6 is connected with the optical input end of the third coupler 9, the optical output end of the third coupler 9 is connected with the optical output end of the second isolator 10, the optical input end of the second isolator 10 is the optical output end of the optical pulse delayer; the electrical output end of the first photoelectric detector 2 is connected with the first electrical input end of the analysis and control system 11, the electrical output end of the second photoelectric detector 5 is connected with the second electrical input end of the analysis and control system 11, the first electrical output end of the analysis and control system 11 is connected with the electrical input end of the pumping light source 6, and the second electrical output end of the analysis and control system 11 is connected with the electrical input end of the piezoelectric ceramic plate 7;
the second coupler 3, the gain annular waveguide 8 and the third coupler 9 form an annular resonant cavity, and the resonant wavelength of the annular resonant cavity is the working wavelength of the optical pulse delayer;
the wavelength of the output light of the pump light source 6, the working wavelength of the first isolator 4 and the working wavelength of the second isolator 10 are the same, but different from the working wavelength of the optical pulse delay unit;
the pumping light source 6 outputs pumping light, the power of the pumping light output by the pumping light source 6 can be adjusted by changing the voltage of the electrical input end of the pumping light source 6, and the pumping light output by the pumping light source 6 can pump the gain annular waveguide 8;
the gain annular waveguide 8 can provide gain for the optical pulse delayer, namely, when the light with the wavelength of the working wavelength of the optical pulse delayer passes through the pumped gain annular waveguide 8, the gain can be obtained;
the length of the piezoelectric ceramic piece 7 is controllable, and the length of the piezoelectric ceramic piece 7 can be adjusted by changing the voltage of the electric input end of the piezoelectric ceramic piece 7, so that the length of the gain annular waveguide 8 and the cavity length of the annular resonant cavity are adjusted;
the first isolator 4 and the second isolator 10 have a one-way conduction effect only on light with the same wavelength as the working wavelength thereof, and have a two-way conduction effect on light with other wavelengths;
the first coupler 1 is a 1 × 2 coupler, the coupling ratio is far greater than 1, and the light intensity entering the second coupler 3 through the first coupler 1 is far greater than the light intensity entering the first photodetector 2 through the first coupler 1;
the second coupler 3 and the third coupler 9 are both 2 × 2 couplers;
the parameters of the first photoelectric detector 2 and the second photoelectric detector 5 are completely the same, and the working wavelengths of the first photoelectric detector and the second photoelectric detector are the working wavelengths of the optical pulse delayer;
the analysis and control system 11 consists of a sampling circuit 11-1, a comparison circuit 11-2, a first output circuit 11-3 and a second output circuit 11-4;
the first electrical input end of the sampling circuit 11-1 is the first electrical input end of the analysis and control system 11, the second electrical input end of the sampling circuit 11-1 is the second electrical input end of the analysis and control system 11, the electrical output end of the first output circuit 11-3 is the first electrical output end of the analysis and control system 11, and the electrical output end of the second output circuit 11-4 is the second electrical output end of the analysis and control system 11; the electrical output end of the first photoelectric detector 2 is connected with the first electrical input end of the sampling circuit 11-1, the electrical output end of the second photoelectric detector 5 is connected with the second electrical input end of the sampling circuit 11-1, the first electrical output end of the sampling circuit 11-1 is connected with the first electrical input end of the comparison circuit 11-2, the second electrical output end of the sampling circuit 11-1 is connected with the second electrical input end of the comparison circuit 11-2, the first electrical output end of the comparison circuit 11-2 is connected with the electrical input end of the first output circuit 11-3, the electrical output end of the first output circuit 11-3 is connected with the electrical input end of the pumping light source 6, meanwhile, the second electrical output end of the comparison circuit 11-2 is connected with the electrical input end of the second output circuit 11-4, the electrical output end of the second output circuit 11-4 is connected with the third electrical input end of the comparison circuit 11-2, And the electrical input of the piezoelectric ceramic plate 7;
the electrical output end of the first output circuit 11-3 outputs a voltage signal, which is loaded to the electrical input end of the pump light source 6 to adjust the power of the pump light output by the pump light source 6;
the electrical output end of the second output circuit 11-4 outputs a voltage signal, which is loaded to the electrical input end of the piezoelectric ceramic plate 7 to adjust the length of the piezoelectric ceramic plate 7, and further adjust the length of the gain annular waveguide 8 and the cavity length of the annular resonant cavity.
The working principle is as follows: the optical input end of the first coupler 1 is the optical input end of the optical pulse delayer, and the optical input end of the second isolator 10 is the optical output end of the optical pulse delayer;
the central wavelength of the optical pulse signal input into the optical pulse delayer needs to be far away from the working wavelength of the first isolator 4 and the working wavelength of the second isolator 10, so that the first isolator 4 and the second isolator 10 do not have a unidirectional conduction effect but have a bidirectional conduction effect on the optical pulse signal input into the optical pulse delayer, otherwise, the effect of the optical pulse delayer cannot be achieved;
the optical pulse signal input into the optical pulse delay device needs to contain a trigger optical pulse, the pulse width (i.e. the pulse duration) of the trigger optical pulse is large and needs to be longer than the response time of the analysis and control system 11, in addition, the trigger optical pulse is positioned at the forefront end of the optical pulse signal, otherwise, the effect of the optical pulse delay device cannot be achieved;
when the optical pulse signal resonates in the ring resonant cavity, the ring resonant cavity can delay the optical pulse signal, and the delay is determined by the coupling ratio of the second coupler 3 and the coupling ratio of the third coupler 9;
as shown in fig. 1, an optical pulse signal input to the optical pulse delayer is input from an optical input end of a first coupler 1, and is divided into two beams after passing through the first coupler 1, because the coupling ratio of the first coupler 1 is much greater than 1, and the light intensity entering a second coupler 3 through the first coupler 1 is much greater than the light intensity entering a first photodetector 2 through the first coupler 1, one beam with smaller light intensity enters the first photodetector 2, and the other beam with larger light intensity enters an annular resonant cavity through the second coupler 3; because the first isolator 4 has a bidirectional conduction effect on the optical pulse signal input into the optical pulse delayer, the optical pulse signal in the annular resonant cavity can be output by the second coupler 3 and enter the second photoelectric detector 5 through the first isolator 4, and meanwhile, because the second isolator 10 has a bidirectional conduction effect on the optical pulse signal input into the optical pulse delayer, the optical pulse signal in the annular resonant cavity can also be output by the third coupler 9 and output by the optical output end of the optical pulse delayer through the second isolator 10;
the pump light output by the pump light source 6 enters the ring-shaped resonant cavity through the third coupler 9, the pump light in the ring-shaped resonant cavity can enter the first isolator 4 through the second coupler 3, because the wavelength of the output light of the pump light source 6 is the same as the working wavelength of the first isolator 4, and the first isolator 4 has a one-way conduction effect on the light with the same wavelength as the working wavelength thereof, the pump light cannot pass through the first isolator 4, meanwhile, the pump light in the ring-shaped resonant cavity enters the second isolator 10 through the third coupler 9, because the wavelength of the output light of the pump light source 6 is the same as the working wavelength of the second isolator 10, and the second isolator 10 has a one-way conduction effect on the light with the same wavelength as the working wavelength thereof, the pump light cannot pass through the second isolator 10 and is output by the light output end of the optical pulse delay unit;
because the trigger light pulse is positioned at the foremost end of the light pulse signal input into the light pulse delayer, the trigger light pulse is divided into two beams after passing through the first coupler 1, one beam with smaller light intensity enters the first photoelectric detector 2 as a reference light signal, the other beam with larger light intensity enters the annular resonant cavity through the second coupler 3, the first photoelectric detector 2 converts the light intensity of the reference light signal into a reference voltage signal, and inputs the reference voltage signal into the analysis and control system 11, the analysis and control system 11 generates a triangular wave voltage signal after receiving the reference voltage signal, and loads the triangular wave voltage signal to the electric input end of the piezoelectric ceramic plate 7 so as to continuously change the length of the piezoelectric ceramic plate 7, further continuously change the length of the gain annular waveguide 8, and continuously change the cavity length of the annular resonant cavity and the continuous change of the cavity length of the annular resonant cavity, so as to continuously change the resonant wavelength of the annular resonant cavity, thus, when the trigger light pulse in the ring resonator is output via the second coupler 3, the intensity of the trigger light pulse is not a fixed value but a variable value, in short, by continuously changing the cavity length of the ring resonator, the transmission spectrum of the trigger light pulse through the ring resonator can be obtained at the optical output end of the second coupler 3, the optical signal of the trigger light pulse through the ring resonator and output by the second coupler 3 is taken as the transmission optical signal, the transmission optical signal is output by the second coupler 3 and enters the first isolator 4, since the first isolator 4 has a bidirectional conduction effect on the optical pulse signal input into the optical pulse delay device, therefore, the transmitted light signal enters the second photodetector 5 through the first isolator 4, the second photodetector 5 converts the light intensity of the transmitted light signal into a transmitted voltage signal, and the transmitted voltage signal is input into the analysis and control system 11;
when the trigger light pulse resonates in the annular resonant cavity, the light intensity of the transmission light signal is minimum, and at the moment, the voltage value of the transmission voltage signal is also minimum;
in the analysis and control system 11, comparing the triangular wave voltage signal with the transmission voltage signal on the same time axis to obtain a voltage value x of the triangular wave voltage signal corresponding to the time of the minimum voltage value of the transmission voltage signal, then generating a direct current voltage signal with an amplitude of x by the analysis and control system 11, using the direct current voltage signal as a resonant direct current voltage signal, and loading the resonant direct current voltage signal to the electrical input end of the piezoelectric ceramic plate 7 to adjust the cavity length of the ring-shaped resonant cavity, so as to adjust the resonant wavelength of the ring-shaped resonant cavity, that is, the working wavelength of the optical pulse delayer, so that an optical pulse after triggering the optical pulse in the optical pulse signal input to the optical pulse delayer resonates in the ring-shaped resonant cavity, thereby generating a delay;
meanwhile, in the analysis and control system 11, the loss of the trigger optical pulse in the ring resonator is obtained from the minimum voltage value of the transmission voltage signal, then, the analysis and control system 11 generates a dc voltage signal with the amplitude of y, the dc voltage signal is used as a pumping dc voltage signal, and the pumping dc voltage signal is loaded to the electrical input terminal of the pumping light source 6 to adjust the power of the pumping light output by the pumping light source 6, so that the pumping gain ring waveguide 8 provides a gain for the optical pulse signal input to the present optical pulse delay, and the optical pulse after the trigger optical pulse in the optical pulse signal input to the present optical pulse delay is made to have a gain equal to the loss in the ring resonator, so that no matter the optical pulse signal input to the present optical pulse delay is output from the optical output terminal of the second coupler 3 or output from the optical output terminal of the third coupler 9 through the ring resonator, the transmissivity of different wavelength components in the optical pulse signal input into the optical pulse delayer is the same and is 1, so that the pulse deformation caused by different transmissivity of different wavelength components in the optical pulse signal is eliminated, and the pulse deformation generated after the optical pulse signal input into the optical pulse delayer is delayed by the annular resonant cavity is very small.
The operating principle of the analysis and control system 11: the first photoelectric detector 2 inputs a reference voltage signal into the sampling circuit 11-1, the sampling circuit 11-1 inputs the reference voltage signal into the comparison circuit 11-2, the comparison circuit 11-2 sends an instruction to the second output circuit 11-4 after receiving the reference voltage signal, so that the second output circuit 11-4 generates a triangular wave voltage signal, and the second output circuit 11-4 loads the triangular wave voltage signal to the electric input end of the piezoelectric ceramic piece 7 and simultaneously inputs the triangular wave voltage signal into the comparison circuit 11-2;
at this time, the second photodetector 5 inputs the transmission voltage signal into the sampling circuit 11-1, the sampling circuit 11-1 inputs the transmission voltage signal into the comparison circuit 11-2, then the comparison circuit 11-2 compares the triangular wave voltage signal with the transmission voltage signal on the same time axis, the voltage value x of the triangular wave voltage signal corresponding to the time of the minimum voltage value of the transmission voltage signal is obtained, the comparison circuit 11-2 inputs the voltage value x into the second output circuit 11-4, the second output circuit 11-4 generates a dc voltage signal with the amplitude of x, that is, a resonant dc voltage signal, the second output circuit 11-4 outputs the resonant dc voltage signal, and the resonant dc voltage signal is loaded to the electrical input end of the piezoelectric ceramic plate 7.
Meanwhile, the comparison circuit 11-2 obtains the loss of the trigger light pulse in the ring resonator from the minimum voltage value of the transmission voltage signal, and obtains a voltage value y to be loaded by the pumping light source 6 when the loss is compensated according to the loss, the comparison circuit 11-2 inputs the voltage value y into the first output circuit 11-3, the first output circuit 11-3 generates a direct current voltage signal with the amplitude of y, namely a pumping direct current voltage signal, and the first output circuit 11-3 outputs the pumping direct current voltage signal and loads the pumping direct current voltage signal to the electrical input end of the pumping light source 6.