41results about How to "Increase cavity length" patented technology

A structure of an interference display cell is provided. The cell comprises a first plate and a second plate, wherein a support is located between the first plate and the second plate. The second plate is a deformable and reflective plate. An incident light from one side of the first plate is modulated and only specific frequency light reflects by the second plate. The frequency of the reflected light is related to the distance between the first plate and the second plate. The support has at least one arm. The arm's stress makes the arm hiking upward or downward. The distance between the first plate and the second plate is also changed. Therefore, the frequency of the reflected light is altered.

An interference display unit with a first electrode, a second electrode and posts located between the two electrodes is provided. The characteristic of the interference display unit is that the second electrode's stress is released through a thermal process. The position of the second electrode is shifted and the distance between the first electrode and the second electrode is therefore defined. A method for fabricating the structure described as follow. A first electrode and a sacrificial layer are sequentially formed on a substrate and at least two openings are formed in the first electrode and the sacrificial layer. A supporter is formed in the opening and the supporter may have at least one arm on the top portion of the supporter. A second electrode is formed on the sacrificial layer and the supporter and a thermal process is performed. Finally, The sacrificial layer is removed.

A method for fabricating an interference display unit is provided. A first plate and a sacrificial layer are formed in order on a substrate and at least two openings are formed in the first plate and the sacrificial layer. A photoresist layer is spin-coated on the sacrificial layer and fills the openings. A photolithographic process patterns the photoresist layer to define a support with an arm. A second plate is formed on the sacrificial layer and posts. The arm's stress is released through a thermal process. The position of the arm is shifted and the distance between the first plate and the second plate is therefore defined. Finally, The sacrificial layer is removed.

The invention is concerned with stabilized frequency method and equipment of double longitudinal modes laser based on thermoelectric cooler. The stabilized frequency method is piezoelectric ceramics, and so on. Detect the circumstance temperature T0 of laser to confirm heat balance temperature Tset, start electrical source of laser to test current temperature Treal of laser tube at real time. Adjust countercurrent I according to different value between current temperature Treal and heat balance temperature Tset and heat up laser tube to keep temperature arrive to Tset. Detect optical power Pm and Pm+1of m order and m+1order on the mutual vertical polarization direction to laser and count the different valueDeltP of the two powers. When the temperature of laser tube is near to heat balance temperature Tset, afford forward or counter current to thermoelectric cooler according to the forward or counter to the different valueDeltP, keep the symmetry of two longitudinal mode laser frequency and make the different valueDeltP close to zero, by controlling the temperature of laser tube, the length of resonant cavity and laser longitudinal mode frequency. The two longitudinal mode frequencies are steady, and this product is fit for stabilized frequency.

The invention discloses a continuous wave optical parametric oscillator with pumping resonance. The continuous wave optical parametric oscillator with the pumping resonance comprises a single frequency pump laser, a beam collimating unit, a first optical isolator, a pump input coupling mirror, a first concave mirror, a nonlinear crystal, a second concave mirror, a dichroic mirror, an optical band pass wave filter and an OPO signal light output coupling mirror. According to the continuous wave optical parametric oscillator, the non-linear crystal is directly placed between the two concave mirrors, and a smaller signal and a spot area of the pump light can be obtained by selecting the concave mirror with short focal length; the cavity length of the signal cavity and the pumping cavity is increased with a folded resonator. Therefore, the spot area of the signal and pump light in the non-linear crystal can be further reduced, and the extremely low oscillation threshold is realized, wherein the oscillation threshold value can be less than 60 MW, or even less than 30 MW. The continuous wave optical parametric oscillator with a low threshold value has the advantages of reducing the power requirement of the pump laser, being relatively simple in structure, and easy to realize miniaturization and practicability.

A laser device for intra-cavity frequency conversion, in particular, for the second harmonic generation, the device comprising a laser cavity, formed by the first and the second laser cavity end reflectors wherein the said laser cavity end reflectors are highly reflective for the radiation about the laser fundamental frequency and as such provide for a predetermined level of circulating inside the cavity fundamental frequency power; an active medium provided within the said laser cavity; at least one non-linear crystal, in particular, for the second harmonic generation provided within the same laser cavity; tuning means adapted for tuning at least one of laser cavity end reflectors; wherein at least one of the laser cavity end reflectors comprises an interferometric layout providing spectrally selective reflection for the radiation about the laser fundamental frequency with the value of reflectivity nearly to 100% within a spectral range close to the free spectrum range of the laser cavity and with a sufficiently lower reflectivity outside the above spectral range such that the laser cavity restricts the spectrum of the laser radiation to a single longitudinal mode.

A terahertz band optical filter having a dielectric multilayer periodic structure in which a plurality of dielectric materials are periodically layered. Multi-cavity layers each having an optical path length of n times λ/2 (n is an integer greater than or equal to 1) and made of a low-refractive index medium are arranged. The cavity layers are coupled using a single-layer coupling layer having an optical path length λ/4 and made of a high-refractive index medium, thus forming a multi-cavity structure. Matching layers each including a high refractive index layer and a low refractive index layer each having an optical path length of λ/4 are disposed at either end of the multi-cavity structure.

The invention provides an external cavity tunable laser and a wavelength tuning method, and belongs to the technical field of lasers. The external cavity tunable laser comprises a semiconductor gain chip, a first collimating lens, a blazed grating and a reflector opposite to the blazed grating, wherein the semiconductor gain chip, the first collimating lens and the blazed grating are located on the same optical axis, and an included angle larger than 0 exists between the grating plane of the blazed grating and the optical axis. The semiconductor gain chip sequentially comprises a sampling grating region, a phase modulation region, a gain region, and a first electrode, a second electrode and a third electrode which respectively cover the sampling grating region, the phase modulation regionand the gain region from left to right. The blazed grating and the reflector are fixed on an electric or manual control mechanical structure. According to the invention, the large-range, rapid and fine tuning of the wavelength by the laser is realized, and the output wavelength can be narrowed.

The invention provides an optical fiber humidity sensor with ultrahigh sensitivity and based on an all-agar F-P cavity and a manufacturing method of the optical fiber humidity sensor. The sensor comprises a leading-in optical fiber and the humidity-sensitive agar F-P cavity composed of an agar colloid. The leading-in optical fiber and the agar F-P cavity are directly connected through an end face dipping method, the leading-in optical fiber is used for leading in a light source signal and transmitting reflected light, and the agar F-P cavity is used for sensing humidity changes in the environment. The agar colloid has hygroscopicity because the surface of the agar colloid contains a large number of hydrophilic groups, the agar colloid can expand when absorbing water and shrink when losing water, and the refractive index and size change at the same time. Changes of the refractive index and thickness of an agar film are fully utilized for manufacturing the sensor, the ultra-short agar F-P cavity can be used as a sensing unit, and therefore ultrahigh sensitivity is obtained. Besides, agar powder is cheap, easy to obtain and easy to dissolve in hot water, the cooled colloid is stable in optical property, the coating process is quite simple, a complicated operation process and expensive equipment are not needed, and the manufacturing cost of the sensor can be lowered.

The invention discloses an in-cavity pump light parameter oscillator with a fiber laser as a pumping source. A pumping source emits in-band laser which is absorbed by a single mode gain fiber, the laser enters the single mode gain fiber via a pump combiner to form population inversion, and laser oscillation is formed in a fiber laser resonant cavity. A non-linear crystal is arranged in the fiber laser resonant cavity, and the in-cavity oscillation laser passes through the non-linear crystal to generate OPO signal light and an OPO idle light. A resonant cavity of the OPO signal light is partially overlapped with the fiber laser resonant cavity, so that the OPO oscillator threshold can be effectively reduced and the power conversion efficiency is improved. The non-linear crystal is arranged between a pair of curved surface mirrors, and an output coupling mirror and a high reflection mirror are used to enhance the cavity length of the OPO signal cavity, so that the light spot area of the OPO signal and the pump light in the non-linear crystal is reduced, and the OPO oscillator threshold is further reduced. Therefore, the OPO oscillator threshold is effectively reduced, the OPO power conversion efficiency is improved, and the structure is simple.

The invention provides a large-cavity length micro-electro-mechanical tunable fabry-perot filter. The upper substrate of the filter is composed of bulk silicon of which the section is W-shaped after double-sided corrosion and a rich boron-doped layer on the lower surface of the bulk silicon; the upper surface of the W-shaped bulk silicon is provided with a transparent thin film as a supporting film; a reflecting film on the supporting film serves as the front cavity mirror of the fabry-perot filter; the rich boron-doped layer in different regions of the lower surface of the W-shaped bulk silicon is capable of serving as a cantilever beam and an upper electrode, respectively. The lower substrate of the filter is made of quartz glass; a rear cavity mirror and a lower electrode are fabricated on the upper surface of the lower substrate in regions corresponding to the front cavity mirror and the upper electrode; a diffraction grating is carved in the region, corresponding to the rear cavity mirror, of the lower surface of the lower substrate. The micro-electro-mechanical filter is capable of obtaining the initial cavity length of more than 200 microns conveniently and capable of realizing single wavelength filtering in different directions, has the advantages of narrow half-peak overall width and wide free spectral range, and has wide application prospect in the fields of optical communication, optical information reading, laser technology and the like.

Disclosed is a top-emitting WOLED display device. An optical turning layer with a uniform thickness is added between anode layers of three sub-pixels R, G and B and a reflective metal layer of the display device. Because of arrangement of the optical turning layer, a distance between a WOLED layer and a reflective metal layer is increased. Thus, a total cavity length of a white OLED is increased, and a microcavity effect of a top-emitting WOLED is overcome. The optical turning layer is suitable for manufacture of AMOLED display devices with high-resolution and color gamut.

The invention discloses a narrow-linewidth tunable laser device and a preparation method thereof. A laser chip sequentially comprises a substrate layer, a lower waveguide layer and an upper waveguidelayer from bottom to top, wherein the lower waveguide layer and the upper waveguide layer are positioned on different planes and perform optical energy exchange through vertical coupling, the lower waveguide layer is provided with an active gain waveguide and a lower-layer passive waveguide which are connected in a butt joint mode, the lower-layer passive waveguide is provided with a plurality ofbent waveguides to prolong the cavity length, the upper waveguide layer is provided with an upper-layer passive waveguide and a micro-ring reflector, the upper-layer passive waveguide and the lower-layer passive waveguide are vertically coupled through a coupler, the micro-ring reflector is coupled with the upper-layer passive waveguide, and the upper-layer passive waveguide is provided with a plurality of bent waveguides to prolong the cavity length. The narrow-linewidth tunable laser device is small in laser chip size, tunable, narrow in linewidth, low in cost and high in stability.

The invention discloses an epitaxial integrated dielectric film DBR external cavity surface emitting laser. The laser comprises a P-type metal electrode layer, a passivation layer, an upper distributed Bragg reflector growing periodically and alternately, an oxidation limiting layer with a high aluminum component, an active region, a lower distributed Bragg reflector growing periodically, a GaAs substrate layer, an N-type metal electrode layer, a current limiting oxidation hole, a phase matching layer, a cavity length matching layer, a silicon oxide and silicon nitride dielectric film distributed Bragg reflector and a light emitting hole; and the inherent cavity length of the vertical cavity surface emitting laser is prolonged by adopting a method of growing a phase matching layer and a cavity length matching layer, and the silicon oxide silicon nitride dielectric film distributed Bragg reflector is extended by adopting an inductively coupled plasma enhanced vapor deposition method, so that the purposes of controlling light polarization and narrowing line width are achieved. The threshold value of the semiconductor laser is reduced, and the yield of the device is improved.

The invention provides a human eye safety laser ranging machine and method. The human eye safety laser ranging machine is simple to operate, small in size, high in test precision and capable of outputting band laser safe to human eyes. The human eye safety laser ranging machine comprises a laser and a detector; the laser comprises a light source, erbium glass and a first reflector and a second reflector; the first reflector and the second reflector are arranged at the light emitting end of the erbium glass; the included angle between the normal of the first reflector and the second reflector and the normal of the light emitting surface of the erbium glass is a Brewster angle; the first reflector, the second reflector and the erbium glass form a V-shaped resonant cavity; light emitted by the light source enters the erbium glass and then is emitted from the first reflector and the second reflector; and the light emitted from the first reflector sequentially passes through a first total reflection mirror, an acous to-optic frequency shifter, a first beam splitter and the detector; the light emitted from the second reflector sequentially passes through a second total reflection mirror, a Q-switched crystal, a Faraday optical rotation isolator, a second beam splitter, a third beam splitter and a telescopic system and then is emitted to a to-be-detected target; and light scattered or reflected by the to-be-detected target sequentially passes through the third beam splitter, the second beam splitter and the first beam splitter and then enters the detector.

The invention provides a method for preparing a vertical cavity laser through perovskite film transfer, and belongs to the technical field of lasers. According to the invention, the hydrophilic flexible substrate is utilized to perform physical and mechanical transfer on the perovskite polycrystalline thin film, the transfer thin film is large in area and high in flatness, and the thickness of the perovskite polycrystalline thin film between DBR reflector substrates can be increased, so that the cavity length of the vertical cavity laser is increased. According to the method, the hydrophilic flexible substrate is adopted to perform physical and mechanical transfer on the perovskite polycrystalline film, so that the surface appearance and the optical property of the perovskite polycrystalline film are not changed, optical loss is not additionally introduced, and the problem that low-solubility perovskite cannot meet the length of an optical resonant cavity due to too small film thickness can be solved; and the application of the device in the laser field is expanded. Meanwhile, the method provided by the invention is simple to operate, low in cost and easy to realize industrial batch production.

An FBG-based diaphragm type high-precision F-P optical fiber acceleration sensor belongs to the technical field of optical fiber sensors. The present invention aims to solve the defects existing in the traditional F-P sensor. Write the FBG in the optical fiber, the sensitive diaphragm, the collimating lens facing the exit end of the optical fiber, the pigtailed sleeve, the optical fiber, and the sleeve; the sensitive diaphragm is set on one end of the sleeve, and the collimating lens and the sleeve are fixed inside the sleeve. With a pigtail sleeve, the pigtail with a pigtail sleeve passes through the other end of the sleeve to connect with the optical fiber, and a raised mass block is set in the middle of the sensitive diaphragm; FBG and the end face of the raised mass block on the sensitive diaphragm constitute A pair of mirrors in the F‑P cavity; the FBG to the fiber exit end face, the collimator lens, and the air cavity from the collimator lens to the raised mass together form the cavity length of the F‑P. The sensitive diaphragm makes the optical fiber sensor have very high sensitivity. The output signal of the sensor is demodulated by phase demodulation method, which has strong anti-interference ability to temperature changes and laser wavelength drift.

The invention relates to a novel folding cavity laser device with opposed right-angle prisms. By utilizing the reflection characteristic of the opposite right-angle prisms, resonance light beams are reflected back and forth between the two right-angle prisms, and the cavity length of a resonance cavity can be effectively increased. The laser device is advantaged in that the cavity length can be remarkably increased in the small space, moreover, the cavity length of the laser device can be greatly adjusted by adjusting a distance between the right-angle prisms so that adjustment of part of laser parameters is realized.

The invention provides an OLED light-emitting device, a display device adopting the OLED light-emitting device and a preparation method of the OLED light-emitting device. Transparent ITO is used as ananode layer of the OLED light-emitting device. A reflecting layer is arranged at the bottom of the anode layer; a dielectric layer is arranged between the anode layer and the reflecting layer; the reflecting layer, the dielectric layer and the anode layer form a first electrode; and the first electrode, the OLED light-emitting layer and the second electrode form an optical resonant cavity. Ny arranging the dielectric layer with a certain thickness, the length of the cavity body of the optical resonant cavity of the OLED light-emitting device is increased, so that the optical resonant cavity has an enhanced emission effect on light with multiple wavelengths in a light-emitting spectrum, and the problems of narrow viewing angle and chromaticity shift of the existing OLED light-emitting device due to a micro-cavity effect are solved.