CN109781389B - High-precision optical fiber fault detection device based on two-dimensional optical microcavity chaotic laser - Google Patents
High-precision optical fiber fault detection device based on two-dimensional optical microcavity chaotic laser Download PDFInfo
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Abstract
The invention discloses a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser, which comprises a packaged optical microcavity integrated chaotic laser, wherein the laser comprises an arc hexagonal laser and a deformed microcavity, one end of the arc hexagonal laser is connected with one end of the deformed microcavity through a passive waveguide II, the other end of the arc hexagonal laser is connected with a passive feedback waveguide, the end surface of the passive feedback waveguide is plated with a high-reflection film, the other end of the arc hexagonal laser is connected with a passive waveguide I, the passive waveguide I outputs light to an optical coupler, the chaotic laser is divided into two beams by the optical coupler, the two beams are respectively probe light I and reference light II, the probe light I is emitted to an optical fiber line to be detected through the optical circulator, and echo signals scattered or reflected in the line are quantized through a photoelectric detector I and an ADC I and then are input to a signal processing device; and the reference light II is directly transmitted to the photoelectric detector II and the ADC II for quantization and then is also input to the signal processing device, and the two signals are subjected to cross-correlation processing to obtain a fault point.
Description
Technical Field
The invention relates to the technical field of photonic integrated chaotic semiconductor lasers, in particular to a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser.
Background
With the wide application of optical fibers in the communication and sensing fields, the optical fiber fault detection device has become an essential tool for optical fiber construction detection and fault maintenance. The commercial fiber fault detection and positioning method is based on an optical time domain reflection technology, the technology is the derivation of a time domain reflectometer in an optical frequency range, the attenuation characteristic of an optical fiber along a propagation direction is detected by observing backward Rayleigh scattering and Fresnel reflection signals of the optical fiber and utilizing the detected signal intensity and return time, the abnormity in a link is further detected and judged, and the position of a fault point is determined, and the currently commonly used fiber fault detection and positioning method comprises a pulse type optical time domain reflection technology, a pseudo-random code modulation optical time domain reflection technology [ EP0269448] and a chaotic optical time domain reflection technology [ CN101226100 ].
The traditional pulsed light time domain reflection technology has inherent defects: if the dynamic range is increased, the peak power of the pulse must be increased or the pulse width must be increased, but the increase of the peak power will generate a nonlinear effect to damage the optical fiber, and the increase of the pulse width will inevitably reduce the spatial resolution of the fault location; the optical time domain reflection technology of pseudo-random code modulation utilizes optical pulse modulated by the pseudo-random code as a detection signal, and obtains distance information between a detection point and a fault point by carrying out correlation processing on the signal, thereby solving the contradiction that the resolution and the dynamic range can not be improved simultaneously, but the length of the pseudo-random code determines the measurement range and the price of a device for generating the high-speed pseudo-random code is high; the chaotic optical time domain reflection Technology is based on a cross-correlation method of chaotic laser signals to realize the detection of optical fiber fault points, the chaotic laser has broadband random oscillation characteristics and higher bandwidth than pseudo-random code signals, and the resolution and dynamic range of an optical time domain reflectometer can be greatly improved (IEEE Photonics Technology Letters, 2008, 20(19): 1636-.
However, most of the existing methods for generating chaotic laser are built by using a semiconductor laser and an external discrete optical element (the length of an external cavity is several meters to dozens of meters), and the chaotic laser has the disadvantages of large volume, complex structure, easy influence from external environment and unstable output. Compared with a device composed of discrete devices, the integrated chip has smaller size, lower cost and better stability, is suitable for mass production, and is concerned by research units of many countries.
In 2008, the first photonic integrated chaotic external cavity feedback semiconductor laser is developed in the PICASSO project of the sixth scientific and technological framework of the european union; in 2010, a double-feedback photonic integrated chaotic semiconductor laser with an air gap was developed by Annovazzi-Lodi et al, university of Pauia, Italy, Mirasso et al, university of Baliazu island, Spanish, and Hamacher, institute of Telecommunications, Frounhf, research institute of Herncies-Hertz, Germany; in 2013, a monolithic integrated semiconductor laser chip is developed by cooperation of the charcot-type semiconductor subject group of southwest university and semiconductor material science focus laboratories of Chinese academy of sciences for generating chaotic laser and the like.
However, the above photonic integrated chaotic semiconductor lasers all adopt a DFB laser delay optical feedback structure, and the generated chaotic laser has obvious delay characteristic information, i.e., the chaotic signal has a certain periodicity, which may cause false alarm and misjudgment on the optical time domain reflectometer. In addition, under the influence of relaxation oscillation of the laser, the energy of the chaotic signal generated by the optical feedback semiconductor laser is mainly concentrated near the relaxation oscillation frequency in the frequency domain, so that uneven frequency spectrum, serious low-frequency suppression and narrow bandwidth are caused, the resolution of the chaotic optical time domain reflectometer can be seriously influenced, and the chaotic optical time domain reflectometer is not beneficial to practical application. Therefore, the invention provides a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser.
Disclosure of Invention
The invention provides a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser, aiming at solving the problems in optical fiber fault detection.
The invention is realized by the following technical scheme: a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser comprises a packaged optical microcavity integrated chaotic laser, wherein the optical microcavity integrated chaotic laser comprises an arc hexagonal laser and a deformation microcavity, one end of the arc hexagonal laser is connected with one end of the deformation microcavity through a passive waveguide II, the other end of the deformation microcavity is connected with a passive feedback waveguide, a high-reflection film is plated on the end face of the passive feedback waveguide, the other end of the arc hexagonal laser is connected with a passive waveguide I, the passive waveguide I in the optical microcavity integrated chaotic laser outputs light to an optical coupler, the optical coupler divides the chaotic laser into two beams, namely a detection light I and a reference light II, the detection light I is transmitted to an optical fiber line to be detected through the optical circulator, and echo signals scattered or reflected in the line are converted into electric signals through a photoelectric detector I, after ADC I quantization, inputting the signal into a signal processing device; and the reference light II is directly transmitted to the photoelectric detector II and is also input to the signal processing device after being quantized by the ADC II.
A fault detection method of a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser comprises the steps that output light of an arc hexagonal laser in a packaged optical microcavity integrated chaotic laser enters a deformed microcavity through coupling of a passive waveguide II, one part of the light is reflected out of the deformed microcavity from the passive waveguide II after being totally reflected through the deformed microcavity, the other part of the light enters a passive feedback waveguide, a high-reflection film reflects the light back into the deformed microcavity, the deformed microcavity is also reflected from the passive waveguide II after passing through an intracavity ray track, the reflected light enters the arc hexagonal laser, finally generated chaotic laser is output through directional coupling of the passive waveguide I at the other end of the arc hexagonal laser, the chaotic laser is output to an optical coupler from the optical microcavity integrated chaotic laser, the optical coupler divides the laser into detection light I and reference chaotic light II, the detection light I is emitted to an optical fiber circuit to be detected through the optical circulator, echo signals scattered or reflected by fault points in the line are converted into electric signals by the photoelectric detector I, and the electric signals are input into the signal processing device after being quantized by the ADC I; and the reference light II is directly transmitted to the photoelectric detector II, is also input to the signal processing device after being quantized by the ADC II, and the two groups of signals are input to the signal processing device for cross-correlation processing and calculating the position of a fault point through the peak position of a cross-correlation curve.
The invention provides a high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser, which mainly comprises a packaged optical microcavity integrated chaotic laser and a photoelectric detector, utilizes the characteristics of wide bandwidth, flat frequency spectrum, small and exquisite structure and capability of eliminating time delay characteristics of the optical microcavity integrated chaotic laser, mainly comprises an arc hexagonal laser and a deformed microcavity, the arc hexagonal laser is the prior art, utilizes the characteristics of large relaxation oscillation frequency and flat small signal modulation response curve, solves the problem of limitation of the relaxation oscillation frequency on the bandwidth by generating a chaotic light source through the laser, the relaxation of the arc edge hexagonal microcavity single-mode semiconductor laser is about 11GHz, the small signal modulation response curve is very flat, and under a certain working current, single mode output with a modulation bandwidth of 13GHz is obtained (Optics Letters, 42(7): 1309 and 1312, 2017). The deformed microcavity is a deformation of the circular optical microcavity, an optical field in the ideal circular optical microcavity is a whispering gallery mode, and a slightly deformed circular cavity can generate a complex ray state and can present a periodic orbit [ J.Opt.Soc.Am.B,21(5):923,2004] along with different light angles, so that the deformed microcavity in the invention performs some slight deformation on the circular cavity, does not limit the deformation, enables the circular cavity to present the periodic orbit along with different light angles, and utilizes the characteristic and adopts the deformed microcavity. The integrated laser is formed by connecting and coupling an arc hexagonal laser and a deformation microcavity through a passive waveguide II, the other end of the deformation microcavity is connected with a passive feedback waveguide, the end face of the passive feedback waveguide is plated with a high-reflection film and used for reflecting light into the deformation microcavity, the other end of the arc hexagonal laser is connected with a passive waveguide I and used for outputting final chaotic laser, the passive waveguide I outputs the light to an optical coupler, the chaotic laser is divided into detection light I and reference light II, the detection light I is sent to an optical fiber circuit to be detected through the optical circulator and used for collecting data, the reference light II is used as reference data and is subjected to cross-correlation processing with the data collected by the detection light I, when the detection light I is sent to the circuit to be detected through the optical circulator, echo signals scattered or reflected in the circuit are converted into electric signals by a photoelectric detector I and then are input to a signal processing device after being quantized, the reference light II is used as reference data, converted into an electric signal through the photoelectric detector II, quantized through the ADC II and then input into the signal processing device, the signal processing device is used for performing cross-correlation processing on the two acquired quantized signals, and fault location is obtained through calculation of cross-correlation curve characteristics (the calculation process of the cross-correlation curve characteristics is known and therefore is not repeated).
Compared with the prior art, the invention has the following beneficial effects: the high-precision optical fiber fault detection device based on the two-dimensional optical microcavity chaotic laser utilizes the characteristics of wide bandwidth, flat frequency spectrum, small structure and capability of eliminating time delay characteristic of the optical microcavity integrated chaotic laser. Compared with a DFB laser, the DFB laser has low relaxation oscillation frequency (several GHz), the response to the relaxation oscillation frequency is far larger than other frequencies, so that chaotic dynamics is dominated by the relaxation oscillation frequency, the frequency spectrum is uneven, the effective bandwidth is low, the university of the tai rationality worker has proposed a method (CN 201410435033.9) for generating chaotic laser with no time delay, flat frequency spectrum and wide band by a photonic integrated chaotic semiconductor laser, the left and right distributed feedback semiconductor laser chips are mainly used for realizing light mutual injection so as to generate the chaotic laser, and the invention adopts an arc edge hexagonal microcavity semiconductor laser as a nonlinear device, and the characteristics of large relaxation oscillation frequency and flat small signal modulation response curve are utilized to replace the DFB semiconductor laser to generate the chaotic light source so as to solve the limitation of the relaxation oscillation frequency to the bandwidth. The two-dimensional optical microcavity is adopted to construct external feedback, light is totally reflected for multiple times in the cavity, a large optical path can be obtained with a small geometric size, long-cavity feedback is realized, the number of external cavity modes induced by the long-cavity feedback is large, and chaos is more easily generated; meanwhile, deformation is introduced into the microcavity, and the complex ray dynamics of the deformed microcavity, namely the total reflection paths of light in the deformed microcavity are different, so that randomly distributed feedback paths are formed, the external cavity resonance characteristic can be eliminated, the generated chaotic laser has high complexity, the bandwidth can reach more than 20G, the broadband chaotic light source enables the optical time domain reflection technology to have higher precision, lower noise and larger dynamic range, the generated chaotic laser has no time delay characteristic, the fault detection is free of false alarm and is easier to identify due to no cycle on the time sequence, the cost required by adopting the photonic integrated chaotic laser is lower, and the practical application requirements are better met.
Drawings
Fig. 1 shows a schematic structural view of the present invention.
FIG. 2 shows an exemplary diagram of an anamorphic microcavity and its optical feedback path in accordance with the present invention.
In the figure: the optical fiber type chaotic laser device comprises an optical microcavity integrated chaotic laser device, 101 passive feedback waveguides, 102 deformed microcavities, 103 passive waveguides II, 104 arc hexagonal laser devices, 105 passive waveguides I, 2 optical couplers, 3 optical circulators, 4 optical fiber circuits to be tested, 5 photoelectric detectors I, 6 ADC I, 7 photoelectric detectors II, 8 ADC II and 9 signal processing devices.
Detailed Description
The following describes an embodiment of the present invention with reference to the drawings.
A high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser is shown in figure 1: the optical microcavity integrated chaotic laser device comprises a packaged optical microcavity integrated chaotic laser device 1, wherein the optical microcavity integrated chaotic laser device 1 comprises an arc hexagonal laser device 104 and a deformed microcavity 102, one end of the arc hexagonal laser device 104 is connected with one end of the deformed microcavity 102 through a passive waveguide II 103, the other end of the deformed microcavity 102 is connected with a passive feedback waveguide 101, a high-reflection film is plated on the end face of the passive feedback waveguide 101, the other end of the arc hexagonal laser device 104 is connected with a passive waveguide I105, the passive waveguide I105 in the optical microcavity integrated chaotic laser device 1 outputs light to an optical coupler 2, the optical coupler 2 divides the chaotic laser into two beams, namely a detection light I and a reference light II, the detection light I is emitted to an optical fiber circuit 4 to be detected through an optical circulator 3, and an echo signal scattered or reflected in the circuit is converted into an electric signal through a photoelectric detector I5, after being quantized by ADC I6, the signal is input into a signal processing device 9; the reference light II is directly transmitted to the photoelectric detector II 7, and is also input to the signal processing device 9 after being quantized by the ADC II 8.
The fault detection method of the high-precision optical fiber fault detection device based on the two-dimensional optical microcavity chaotic laser provided by the embodiment comprises the following specific processes: the output light of the arc hexagonal laser 104 in the packaged optical microcavity integrated chaotic laser 1 is coupled into the deformed microcavity 102 through the passive waveguide II 103, one part of the light is reflected out of the deformed microcavity 102 from the passive waveguide II 103 after being totally reflected through the deformed microcavity 102, the other part of the light enters the passive feedback waveguide 101, the light is reflected back into the deformed microcavity 102 by the high-reflection film, the deformed microcavity 102 is also reflected out of the passive waveguide II 103 after passing through an intracavity ray track, (for example, a certain intracavity ray track is shown in figure 2), the reflected light enters the arc hexagonal laser 104, the chaotic laser is generated by disturbance, the generated chaotic laser is finally output by the passive waveguide I105 at the other end of the arc hexagonal laser 104 in a directional coupling manner, the chaotic laser is output from the microcavity integrated chaotic laser 1 to the chaotic laser 2, the chaotic laser 2 divides the chaotic laser into detection light I and reference light II, the detection light I is transmitted to an optical fiber circuit 4 to be detected through an optical circulator 3, an echo signal scattered or reflected by a fault point in the circuit is converted into an electric signal through a photoelectric detector I5, and the electric signal is input into a signal processing device after being quantized through an ADC I69, placing; the reference light II is directly transmitted to the photoelectric detector II 7, is quantized by the ADC II 8 and then is input to the signal processing device 9, two groups of signals are input to the signal processing device 9 for cross-correlation processing, and a fault point is obtained through cross-correlation curve characteristics, in the embodiment, the generated chaotic laser is assumed to accord with the characteristics of a non-periodic function f (t), the chaotic laser is divided into the detection light I and the reference light II by the optical coupler and respectively satisfy functional relations k f (t) and (1-k) f (t), and the detection light I satisfies the functional relation g (t) = k f (t-τ 0). After the two signals are processed respectively to obtain digital signals, the digital signals enter the signal processing device 9, and the function of the cross-correlation processing is as follows:
wherein, tau0Is the round trip time of the probe light whenτ=τ 0There is a peak in the cross-correlation function, the peak of the cross-correlation function being related to the intensity of the reflected light (US 8502964B 2). Based on the principle, the intensity and round trip time of the reflected detection light can be obtained by the cross-correlation instrument or the computer for processingτ 0Therefore, fault location and transmission characteristic detection of the optical fiber circuit are achieved.
The scope of the invention is not limited to the above embodiments, and various modifications and changes may be made by those skilled in the art, and any modifications, improvements and equivalents within the spirit and principle of the invention should be included in the scope of the invention.
Claims (2)
1. A high-precision optical fiber fault detection device based on a two-dimensional optical microcavity chaotic laser is characterized in that: the optical microcavity integrated chaotic laser device comprises a packaged optical microcavity integrated chaotic laser device (1), wherein the optical microcavity integrated chaotic laser device (1) comprises an arc hexagonal laser device (104) and a deformable microcavity (102), one end of the arc hexagonal laser device (104) is connected with one end of the deformable microcavity (102) through a passive waveguide II (103), the other end of the deformable microcavity (102) is connected with a passive feedback waveguide (101), a high-reflection film is plated on the end face of the passive feedback waveguide (101), the other end of the arc hexagonal laser device (104) is connected with a passive waveguide I (105), the passive waveguide I (105) in the optical microcavity integrated chaotic laser device (1) outputs light to an optical coupler (2), the optical coupler (2) divides laser into two beams which are chaotic probe light I and reference light II respectively, and the probe light I is emitted to an optical fiber circuit (4) to be detected through an optical circulator (3), echo signals scattered or reflected in a line are converted into electric signals by a photoelectric detector I (5), and the electric signals are input into a signal processing device (9) after being quantized by an ADC I (6); the reference light II is directly emitted to the photoelectric detector II (7), and is quantized by the ADC II (8) and then input to the signal processing device (9).
2. The fault detection method of the high-precision optical fiber fault detection device based on the two-dimensional optical microcavity chaotic laser as claimed in claim 1, is characterized in that: the packaged optical microcavity integrated chaotic laser (1) is characterized in that an arc hexagonal laser (104) outputs light, the light is coupled into a deformed microcavity (102) through a passive waveguide II (103), one part of the light is reflected out of the deformed microcavity (102) from the passive waveguide II (103) after being totally reflected through the deformed microcavity (102), the other part of the light enters a passive feedback waveguide (101), a high-reflection film reflects the light back into the deformed microcavity (102), the light is reflected out of the deformed microcavity (102) from the passive waveguide II (103) after passing through an intracavity ray track, the reflected light enters the arc hexagonal laser (104), finally generated chaotic laser is directionally coupled and output through a passive waveguide I (105) at the other end of the arc hexagonal laser (104), the chaotic laser is output to an optical coupler (2) from the optical microcavity integrated chaotic laser (1), the chaotic laser is divided into detection light I and reference light II by the optical coupler (2), the detection light I is transmitted to an optical fiber line (4) to be detected through an optical circulator (3), an echo signal scattered or reflected by a fault point in the line is converted into an electric signal through a photoelectric detector I (5), and the electric signal is quantized through an ADC I (6) and then input into a signal processing device (9); the reference light II is directly emitted to the photoelectric detector II (7), is quantized by the ADC II (8) and then is input to the signal processing device (9), the two groups of signals are input to the signal processing device (9) to be subjected to cross-correlation processing, and the position of a fault point is calculated through the peak position of a cross-correlation curve.
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| WO2010126427A1 (en) * | 2009-04-30 | 2010-11-04 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for fault discovery in a passive optical network (pon) |
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