45results about How to "Guaranteed coherence" patented technology

The invention relates to the distributed optical fiber sensing technique, in particular to a distributed optical fiber multi-parameter sensing measurement system. The distributed optical fiber multi-parameter sensing measurement system solves the problem that according to an existing distributed optical fiber sensor, vibration information of sensing optical fibers can not be monitored. The distributed optical fiber multi-parameter sensing measurement system comprises a super-narrow-linewidth high-power optical fiber laser, a first 1*2 optical coupler, a single-side-band carrier suppression modulator, a second 1*2 optical coupler, a third 1*2 optical coupler, an electrooptical modulator, a first 2*1 optical coupler, a scrambler, an integrated wavelength division multiplexer, sensing optical fibers, a full-optical-fiber narrow-band low-noise Brillouin frequency shift, a narrow-band fiber bragg grating transmission filter, a second 2*1 optical coupler, a third 2*1 optical coupler, a first low-bandwidth high-gain photoelectric detector, a second low-bandwidth high-gain photoelectric detector and a data acquisition processing system. The distributed optical fiber multi-parameter sensing measurement system is suitable for various measurement fields.

The invention provides a radar echo reconstruction method based on adjacent wave correlation and phase layering. The method comprises the following steps: carrying out phase alignment through adjacent wave correlation: sampling adjacent echo pulses, carrying out correlation operation on the obtained sampled signals, and realizing echo phase pre-alignment according to the peak value of correlation result; establishing a phase difference sequence of an echo sampling sequence and carrying out linear fitting, and layering the phase difference sequence into a plurality of combinations having the same slope; and carrying out screening and reconstruction on the radar echo according to the layering result and utilizing the final reconstructed radar echo to carry out frequency estimation and speed calculation. The method is used for solving the problems of unaligned phase due to emission signals and echo correlation as well as echo phase jump due to object motion state or signal forwarding mechanism, thereby reducing speed measurement error when the object maneuver is large.

The invention discloses a distributed sensing system based on delayed pulse Raman amplification, which comprises a narrow linewidth light source, a Raman pumping light source, a first modulation module connected to the narrow linewidth light source, and a Raman pumping light source The second modulation module, the first modulation module is connected to the wavelength division multiplexer through the erbium-doped fiber amplifier and the circulator in turn, the second modulation module is directly connected to the wavelength division multiplexer, and the wavelength division multiplexer The circulator is connected to the sensing fiber, the first modulation module is connected to the second modulation module through a signal generator, and the circulator is sequentially connected to the detector, the data acquisition module and the computer through a filter. The invention realizes longer effective sensing distance of detection light by means of pulse modulation pumped Raman amplification with a certain time delay.

The invention provides a high-power vertical cavity surface emitting laser with an integrated light emitting area. The high-power vertical cavity surface emitting laser comprises an emitting hole anda conductive layer, wherein an isolation groove is formed in the emitting hole, the emitting hole is partially isolated to form a long and narrow emission area which is communicated, and an insulatinglayer is arranged in an isolation layer; the conductive layer is filled in the isolation groove, extends towards the two sides and forms an ohmic contact with the long and narrow emission area. According to the emitting laser, the emitting hole of the vertical cavity surface emitting laser with the large oxidation aperture is isolated into the long and narrow emission area, and the long and narrow emission area is in contact with the conductive layer, so that the current path in the emitting hole is prolonged, and the current density of the middle area of the vertical cavity surface emittinglaser with the large oxidation aperture can be effectively increased; in addition, the current can be transversely transmitted from the conductive layer, so that the uniformity of the current densitydistribution in the light-emitting hole is greatly improved, and the conversion efficiency is improved. Meanwhile, the coherence of emergent light is kept in a large range. The laser can be applied tothe fields of laser radars, infrared cameras, depth recognition detectors and the like.