47results about How to "Broaden the spectral width" patented technology

A grating-outcoupled microcavity disk resonator has whispering gallery modes existing in a nearly circular resonator. Light is outcoupled by providing a grating region in the plane of the grating-outcoupled microcavity disk resonator. The grating region provides an outcoupling or lass mechanism that symmetrically interacts with the clockwise and counterclockwise whispering gallery modes, thereby making the resonator capable of surface emission.

An illumination light source is provided with a laser light source having a laser medium with a specified gain region, and a reflector having a narrow band reflection characteristic. A part of a laser light emitted from the laser light source is reflected and fed back by the reflector, so that an oscillation wavelength of the laser light source is fixed at a reflection wavelength. A peak of the gain region of the laser medium is shifted from the reflection wavelength by a change of an oscillation characteristic of the laser light source, so that the oscillation wavelength of the laser light source is changed from the reflection wavelength. Thus, an oscillation spectrum of the laser light source is spread to reduce speckle noise.

This invention pertains to a device for broadening optical wavelength in the 2-14 μm region comprising a light source and a highly nonlinear chalcogenide fiber associated therewith whereby a light signal is passed from the light source into the fiber wherein and through interactions between the light signal and the material, bandwidth of the light signal is broadened in the 2-14 μm region.

A light source device including a seed light generation device, a light amplification unit which optically amplifies seed light generated by the seed light generation device, and a wavelength conversion unit which converts the wavelength of the light optically amplified by the light amplification unit. The seed light generation device includes a pulsed light generation unit which generates pulsed light having a single wavelength, a pulse modulation unit which selectively passes and extracts a part of the pulsed light, and a timing adjustment unit which relatively adjusts the extracting timing of the pulsed light by the pulse modulation unit during the generation period of the pulsed light by the pulse generation unit, according to an operation.

Provided is a communication method of a secondary transmitter included in a multiple-antenna based multiple input multiple output (MIMO) cognitive radio communication system, the method including: estimating an interference channel between the secondary transmitter and a primary user in each of at least one first spectrum band that is being used in a primary system; calculating an orthogonal projection matrix to cancel interference with respect to the primary user from the interference channel; calculating an effective channel between the secondary transmitter and a secondary receiver based on the to orthogonal projection matrix; and selecting an index of an optimal spectrum band from the at least one first spectrum band based on the orthogonal projection matrix and the effective channel.

The invention relates to an optical fiber sensing natural gas pipeline leakage accident recognition device and relates to the technical field of mechanical vibration measuring, impact measuring and pipeline systems. The optical fiber sensing natural gas pipeline leakage accident recognition device comprises a light source, a transmission optical path part, optical fiber sensors, a photoelectric detector and a signal collecting and processing module. The optical fiber sensors are installed on a pipeline body at certain intervals and form optical fiber sensor groups, each optical fiber sensor group is connected with a beam splitter serially connected in optical fibers through an optical fiber and then is connected with the light source and photoelectric detector at the receiving end, and the output of the photoelectric detector is connected with the signal collecting and processing module which is connected with a microcomputer. Through processing of the signal collecting and processing module, the sensor group signals mixed based on a frequency division multiplexing mode achieve demultiplexing of sensors in the sensor groups to obtain original leakage vibration wave signals. The optical fiber sensing natural gas pipeline leakage accident recognition device can timely monitor abnormal signals at the primary stage of pipeline leakage and is high in alarming accuracy.

In an optical coherence tomography apparatus: low-coherence light from a light source is split into signal light and reference light; at least one of the frequencies of the signal light and the reference light is shifted so as to produce a predetermined frequency difference between the frequencies; the reference light and a portion of the signal light reflected from the object are optically multiplexed so as to produce interference light; and the optical intensity of the interference light is detected in order to obtain a tomographic image of the object. In the light source, the pulse width of pulsed light emitted from a pulsed light source unit is reduced by an optical-waveguide structure. The optical-waveguide structure is made of a material having a normal dispersion characteristic, and includes a structure which realizes an anomalous dispersion characteristic so as to reduce the pulse width of the pulsed light.

The invention provides a device and a method for expanding spectral widths. The device for expanding the spectral widths comprises a spectroscope, a first plane mirror, a second plane mirror and a focusing lens. The spectroscope is used for respectively carrying out reflex and transmission on laser pulses coming from an incidence end in an incident mode. The first plane mirror is used for carrying out reflex on a laser pulse which is reflected by the spectroscope. The second plane mirror is used for carrying out reflex on a laser pulse which is transmitted by the spectroscope. The distance between the first plane mirror and the spectroscope is unequal to the distance between the second plane mirror and the spectroscope. The spectroscope is further used for transmitting the laser pulse which is reflected by the first plane mirror to the focusing lens, and for reflecting the laser pulse which is reflected by the second plane mirror to the focusing lens. The focusing lens is used for outputting the two incident laser pulses to an optical fiber through an outgoing port. Through controlling on the sequence by which the two laser pulses enter the optical fiber, strong orphans of the two laser pulses are crashed in the optical fiber, and the spectral widths of the output laser pulses are expended.

The invention relates to a laser system with a passively Q-switched laser 1, a spectrally widening element 3, and a compression element 4. Laser systems of this kind are utilized for generating ultra-short laser pulses. Systems, mode-coupled solid-state lasers known from prior art allow for generating laser pulses in the sub-10 ps range only with complicated and alignment-sensitive free-beam arrangements. Therefore, it is the object of the present invention to create a laser system that generates pulse durations of less than 10 ps and which is simple and compact to produce at the same time. In order to achieve this object, the present invention proposes that the passively Q-switched laser 1 is provided with a longitudinally monomode output radiation which is spectrally widened by means of the spectrally widening element 3 by self-phase modulation and is temporally compressed by the compression element 4.

The invention relates to the technical field of laser, and aims to solve the problems that an existing speckle eliminating method is complex and influences the service life of a laser system. A semiconductor laser light source and a laser projector are provided. The semiconductor laser light source comprises a laser diode array and a driving module, the laser diode array comprises at least two laser diode groups with different central wavelengths. Each laser diode group comprises one or more laser diodes with the same central wavelength; the number of the driving modules is the same as that of the laser diode groups; the driving modules are connected with the corresponding laser diode groups; and the driving module is used for providing corresponding driving currents for the correspondinglaser diode groups, so that the difference value of the total light output power of any two laser diode groups in the laser diode array is within a preset range, and the total light output power is the sum of the light output power of all laser diodes in the laser diode groups. The method can effectively reduce speckle contrast.