41results about How to "Narrow spectral width" patented technology

An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.

A compact mid-IR laser device utilizes an external cavity to tune the laser. The external cavity may employ a Littrow or Littman cavity arrangement. In the Littrow cavity arrangement, a filter, such as a grating, is rotated to provide wavelength gain medium selectivity. In the Littman cavity arrangement, a reflector is rotated to provide tuning. A quantum cascade laser gain medium provides mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens for both the output lens and the external cavity lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser gain medium is thermally coupled. The heat spreader not only serves to dissipate heat and conduct same to the TEC, but also serves as an optical platform to secure the optical elements within the housing in a fixed relationship relative on one another. The small diameter aspheric output and external cavity lens each may have a diameter of 10 mm or less and each lens is positioned to provided a collimated beam output from the quantum cascade laser gain medium. The housing is hermetically sealed to provide a rugged, light weight portable MIR laser source.

A compact mid-IR laser device utilizes a quantum cascade laser to provide mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser is thermally coupled.

A compact mid-IR laser device utilizes a quantum cascade laser to provide mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser is thermally coupled. The heat spreader not only serves to dissipate heat and conduct same to the TEC, but also serves as an optical platform to secure the optical elements within the housing in a fixed relationship relative on one another. A small diameter aspheric lens may have a diameter of 10 mm or less and is positioned to provided a collimated beam output from the quantum cascade laser. The housing is hermetically sealed to provide a rugged, light weight portable MIR laser source.

A high power diode laser system utilizes an external cavity to narrow the spectral width of a high power multimode diode laser to change the output power normally produced by the diode from a broad spectrum to a very narrow spectrum. The power output of the laser system is concentrated over a narrow spectral range which falls within the useable range for particular applications, such as optical pumping of noble gas samples for magnetic resonance imaging. The output of the diode is received by a collimating element which directs the light on a beam path to a diffraction grating which is oriented at an angle to the incident beam. A portion of the beam may be directed from the diffraction grating to provide useable output light, and a portion of the light incident on the grating is directed back to be focused on the diode to provide feedback to cause the diode to preferentially lase at the wavelength of the light that is fed back. A polarization rotation element may be used to orient the polarization of the light passing through it to control the amount of feedback light.

The invention belongs to the field of quantum private communication and specifically relates to a single photon source based on a Faraday-Sagnac loop and a realization method thereof. The single photon source is characterized in that a system of the single photon source includes a laser device, a circulator, a polarization analyzer and the Faraday-Sagnac loop which includes a four-port optical-fiber beam splitter, a phase modulator and a Faraday rotating mirror. Continuous light output by the laser device enters the four-port optical-fiber beam splitter via the circulator. The four-port optical-fiber beam splitter divides the continuous light into two beams of orthogonal-linear polarized light, which are identical in amplitude and phase. The two beams of linear polarized light are transmitted in opposite directions along the Faraday-Sagnac loop and modulated by the phase modulator at different moments. The two beams of modulated linear polarized light are overlaid in the four-port optical-fiber beam splitter and then enter the polarization analyzer after being coupled by the circulator. The advantages of the single photon source based on the Faraday-Sagnac loop are that generated light pulses have a high extinction ratio and a narrow spectral width so that polarization dispersion of the light pulses which are transmitted in a long-distance optical fiber is reduced.

A light source apparatus includes an optical resonator formed by an optical amplification medium and an optical switch. The optical switch includes a saturable absorber and changes its transmittance or reflectance when receiving an optical pulse emitted from a light irradiation source which includes a wavelength-tunable light source. The light source apparatus emits amplified light from the optical resonator in correspondence with the center wavelength of the optical pulse from the wavelength-tunable light source. The relationship between a length L and an effective refractive index n of the optical resonator and a repetition frequency f of the optical pulse satisfies a condition L<c/(nf), and a relationship between the length L and a recovery time τ in which the changed transmittance or reflectance of the optical switch recovers satisfies a condition τ>(nL)/c.

The invention provides a display panel, a manufacturing method thereof and a display device, and relates to the technical field of display. A light emitting device layer is arranged on a driving backboard, a packaging layer, a color film layer and a light absorption layer are arranged on the side, away from the driving backboard, of the light emitting device layer, and the light absorption layer is configured to absorb light with the specific wavelength in external environment light and light emitted by the light emitting device layer; and the specific wavelength includes at least one of a wavelength between the red light band and the green light band, a wavelength between the green light band and the blue light band, and at least one of a wavelength less than the blue light band, and a wavelength greater than the red light band. The absorption layer is added in the display panel, and the light absorption layer absorbs light with a specific wavelength in external ambient light and light emitted by the light emitting device layer, so that the spectral width of the light emitted from the light emitting surface of the display panel is narrowed, and the color purity of the light emitted from the light emitting surface of the display panel is improved; therefore, the display effect of the display panel is improved.

A narrow band laser apparatus may include: a laser resonator; a pair of discharge electrodes; a power supply; a first wavelength measurement device configured to output a first measurement result; a second wavelength measurement device configured to output a second measurement result; and a control unit. The control unit calibrates the first measurement result, based on a difference between the second measurement result derived when the control unit controls the power supply to apply a pulsed voltage to the pair of discharge electrodes with a first repetition frequency and the second measurement result derived when the control unit controls the power supply to apply the pulsed voltage to the pair of discharge electrodes with a second repetition frequency, the second repetition frequency being higher than the first repetition frequency.

The invention discloses a laser emission module for lidar, which is characterized in that a semiconductor laser chip in the module is a horizontal cavity surface emitting laser (HCSEL) chip, and the laser light emitting by the HCSEL chip is collimated in at least one direction, so that the optical system is simplified; the laser emission module is enabled to have the characteristics of small central wavelength range, narrow spectral width, small wavelength temperature drift and the like without adding any optical devices through grating mode locking, and the HCSEL can simultaneously have a large light emitting area and a high-quality beam, thereby achieving the laser characteristics of high power, high brightness and uniform beam, and being very suitable for the application of long-distance and high-precision lidar. In addition, the power density of the light emitting surface is reduced due to the large light emitting area, and the life of the device is correspondingly prolonged. The laser chip structure and light emitting mode of the HCSEL can also reduce the chip cost and facilitate the integration with other optical devices in the module.

A semiconductor laser according to the present invention comprises: a substrate; an n-cladding layer disposed on the substrate; an active layer disposed on the n-cladding layer; a p-cladding layer disposed on the active layer and forming a waveguide ridge; and a diffraction grating layer disposed between the active layer and the n-cladding layer or the p-cladding layer and including a phase shift structure in a part of the diffraction grating layer in an optical waveguide direction. The width of the p-cladding layer is increased in a portion corresponding to the phase shift structure of the diffraction grating layer.

The present invention provides a method for narrowing a spectral width that can also be adapted to an ultrashort optical pulse emitted from a wavelength tunable light source, and that can provide an output optical pulse with a narrow spectral width and a low noise component, and an optical element and a light source device that use the method for narrowing a spectral width. The method includes using an optical waveguide member (2) to cause a soliton effect in an input optical pulse (1) within the optical waveguide member (2), thereby narrowing a spectral width of the input optical pulse (1) to provide an output optical pulse (3), the optical waveguide member (2) having dispersion characteristics such that the average of a second-order dispersion value (β2) with respect to the input optical pulse (1) is negative, and the absolute value of the second-order dispersion value (β2) increases in a propagation direction of the input optical pulse (1).

A visible light communication intensity-enhanced receiving system of the invention comprises a visible light illumination and communication transmitting unit, a transmitting antenna, a receiving focusing lens, a passive light conversion material, a narrow-band filter, a light amplifier, a photoelectric detector, and a signal processing unit. The visible light illumination and communication transmitting unit loads modulation information on a light source, and transmits modulated information via the transmitting antenna to a free space. The receiving focusing lens collects visible light signals. When the collected visible light signals pass through the passive light conversion material, received visible light energy is compressed and converted into a narrow spectrum in a concentrated manner. The compressed spectrum is filtered by the narrow-band filter at the focal plane of the receiving focusing lens and sent to the light amplifier for narrow spectrum amplification. The amplified narrow spectrum is converted by the photoelectric detector into electrical signals. Finally, the electrical signals are demodulated by the signal processing unit to get communication information. The system has very good application, improves the communication distance of visible light, and is practical.