CN208172295U - A kind of deep ultraviolet multi-quantum well waveguide - Google Patents

Abstract

The utility model belongs to optical signal prosessing device technical field,It is related to a kind of deep ultraviolet multi-quantum well waveguide and preparation method thereof,Main structure includes lower protective layer,Substrate layer,Sandwich layer,Clad and up-protective layer,Two or more combined material is used on substrate layer,Grow the alternate low-index layer of high/low refractive index and high refractive index layer,Low-index layer and high refractive index layer are etched into rectangular restricted area as sandwich layer again,In the surrounding growth clad of sandwich layer,Finally following table sheath and up-protective layer are grown respectively in the bottom surface of substrate layer and the top surface of clad,Obtain the ultraviolet multi-quantum well waveguide of rectangular configuration,The effective refractive index for freely changing sandwich layer by the number of plies and thickness of design low-index layer and high refractive index layer is poor,Flexible mentality of designing is provided for deep ultraviolet Quantum Well waveguide,Simple structure and production method；It is smaller to deep ultraviolet absorption in deep ultraviolet band, can be as the raw material of various fiber waveguide devices.

Description

A kind of deep ultraviolet multi-quantum well waveguide

Technical field：

The utility model belongs to optical signal prosessing device technical field, is related to a kind of deep ultraviolet multi-quantum well waveguide, uses Two or more combined material, by growing high/low refractive index alternating layer, application and preparation is in the more of deep ultraviolet band Quantum Well waveguide plays a significant role in fields such as bio-sensing, health care and hydrospace detections.

Background technique：

Multiple quantum wells (multiple quantum well) refers to the system that multiple Quantum Well are combined, Multiple-quantum Trap can also be made of the unmatched two kinds of materials of lattice.If lattice mismatch in certain limit (less than 7%), and strain The thickness of material is no more than critical thickness, so that it may by the difference between elastic deformation compensation lattice constant, and not produce at interface Raw dislocation and defect, this multiple quantum wells are known as strained quantum well.Since the elastic deformation in lattice influences band structure, in this way It is again more that a kind of means of " cutting out " energy band --- InGaAsP/InP long wavelength is made using the characteristics of strained quantum well in strain (1.3 microns) Strained Quantum Well Lasers, threshold current substantially reduce, and characteristic temperature correspondinglys increase.Semiconductor cascade is infrared to swash Light device and cascade thz laser, are all the areas P+N-N+ Jie Zhong N- that multiple quantum wells is placed in reverse bias, more using electronics Trap sequential tunneling realizes laser, and optical maser wavelength depends on the energy difference between subband.Optical waveguide (optical waveguide) It is guidance light wave in the medium apparatus wherein propagated, also known as dielectric optical waveguide, optical waveguide has two major classes：One kind is integrated light wave It leads, including plane (film) dielectric optical waveguide and slab dielectric optical waveguide, is usually all in integrated optoelectronic device (or system) A part, so being called integrated light guide；Another kind of is cylindrical light waveguide, commonly referred to as optical fiber (optical fiber).Optical waveguide The leading structure for the transmission optical frequency electromagnetic wave being made of light transparent medium (such as quartz glass), the transmission principle of optical waveguide are different from Metal enclosed waveguide, on the dielectric interface of different refractivity, the total reflection phenomenon of electromagnetic wave make light wave be confined to waveguide and It is propagated in finite region around it；Multimode and single mode optical fiber have been applied successfully to communicate, and the transmission characteristic of optical fiber is to the external world The factors such as temperature and pressure are sensitive, thus can be made into fibre optical sensor, for measuring the physical quantitys such as temperature, pressure, sound field.Plane Dielectric optical waveguide is simplest optical waveguide, is that the silicon (or GaAs or glass) for being n2 with refractive index makees substrate, uses microelectronics Technique plates the deielectric-coating that one layer of refractive index is n1 on it and usually takes n1 along with refractive index is made of the coating of n3>n2 >N3, so that light wave to be confined to propagate in deielectric-coating.Slab dielectric optical waveguide is that one is generated in the matrix that refractive index is n2 Refractive index is the strip of n1, takes n1>N2, so that light wave to be confined to propagate in strip, this optical waveguide is commonly used for the branch of light The function elements such as device, coupler, switch.When the lateral dimension of optical waveguide is more much larger than the wavelength of light, produced by the fluctuation of light Diffraction phenomena can generally omit and disregard, light can be handled with laws of geometrical optics in propagation problem wherein, such as integrated light wave It leads and in step index optical fiber, be all to be greater than critical angle using incidence angle to be totally reflected light on boundary, as a result light is just It is propagated wherein along dog leg path, in gradient index fibre, then using light gradually toward the curved rule in the big direction of refractive index, Propagate light wherein along curved path.When the lateral dimension of optical waveguide and the wavelength of light are not much different, the fluctuation institute of light The diffraction phenomena of generation just cannot omit, and the electromagnetic theory that need to be used up handles light in propagation problem wherein, i.e., by max Wei equation group is set out, and boundary condition is listed, and solves distribution and propagation characteristic of the electric and magnetic fields of light wave in optical waveguide, thus Solve relevant issues, calculation shows that, for the optical waveguide of a kind of given shape and refractive index, can in the light wave wherein propagated, Various different forms are distributed in electric and magnetic fields, each form is called a kind of transmission mould, referred to as mould；Every kind of mould is all deposited In a cutoff frequency, if the frequency of light wave is lower than this cutoff frequency, the light of this mould cannot pass in the optical waveguide It broadcasts.The diameter of optical fiber is bigger, and the modulus that can be transmitted is more, and the optical fiber that can transmit a variety of moulds is called multimode fibre；One can only be transmitted The optical fiber of kind mould is called single mode optical fiber；Multimode fibre is usually used in short range transmission, such as endoscope；Single mode optical fiber is then used for long distance From communication.

A kind of multiple-quantum well waveguide butt-coupling method disclosed in Chinese patent 02124387.5 includes the following steps：(1) It is epitaxially grown on the substrate the multi-quantum pit structure of component A；(2) after depositing a layer dielectric, mask lithography erodes A platform Multi-quantum pit structure other than item, the deielectric-coating are silica or silica；(3) multiple quantum wells of extension component B again Structure；(4) mask lithography removes the bad part of the interface A and B growth quality；(5) last large area epitaxial optimization designs Body material, while the upper waveguide as component A and B and the coupled waveguide between them；Chinese patent A kind of cladding Effects of GaAs/AlGaAs Quantum Wells waveguide laser of unsymmetrical metal grating disclosed in 201410104279.8 include on to Under the upper metal grating layer, active layer, lower metal carbonyl coat and the substrate that are sequentially stacked, wherein the upper metal grating layer and lower gold Belong to clad to consist of metal, production has one-dimensional barcode metal grating in the upper metal grating layer；The active layer be by Mqw material is constituted；The upper metal grating layer is different with the surface texture of lower metal carbonyl coat, metal grating layer on this It can be by light field local in the active layer with lower metal carbonyl coat；A kind of plane disclosed in Chinese patent 201510073921.5 Optical waveguide includes：The refractive index of under-clad layer, waveguide core layer, separation layer and top covering, the top covering and the under-clad layer is equal And it is higher than the refractive index of the separation layer, the separation layer is formed on the under-clad layer, and the waveguide core layer is coated completely In the separation layer, the top covering is formed on the separation layer；The fusing point of the separation layer is lower than the waveguide core layer Fusing point, and fill each gap of the waveguide core layer；The fusing point of the top covering is lower than the fusing point of the waveguide core layer；Institute The material for stating waveguide core layer is the silica of doped germanium, and the material of the under-clad layer is silica；The material of the separation layer Material is the silica doped with fluorine and germanium, wherein the doping quality of the fluorine is the 1-2% of the silica quality, it is described The doping quality of germanium is the 3-6% of the silica quality, and the doping mass ratio of the fluorine and germanium is greater than 1:3；On described The material of covering is the silica doped with fluorine and germanium, wherein the doping quality of the fluorine is the 1- of the silica quality 3%, the doping quality of the germanium is the 3-6% of the silica quality, and the doping mass ratio of the fluorine and germanium is 1:3； A kind of planar optical waveguide disclosed in Chinese patent 201280067966.6 includes：One planar light substrate has an edge table Face and the unthreaded hole being located on the edge surface including an optical waveguide, the optical waveguide with one；And a pipe, it is formed The planar light substrate is fixed to be defined as lumen for receiving a ferrule and one with a size Edge surface on the edge surface a, so that section of the lumen at the edge surface of the pipe and the unthreaded hole pair It is quasi-：A kind of planar optical waveguide that end face is lens disclosed in Chinese patent 201410842767.9 includes：One planar optical waveguide battle array Column, include multiple planar optical waveguides disposed in parallel, and the spherical mirror end face that multiple planar optical waveguide has had lens, The spherical mirror end face has collimation or focusing function；And a coupler, it is used to support and fixes the planar optical waveguide array；In A kind of hot non-sensitive type planar optical waveguide disclosed in state's patent 201520474486.2 includes：Basal layer and sandwich layer, the sandwich layer It is formed on the basal layer, further includes the top covering for being coated on the sandwich layer surrounding；Top covering material includes ultraviolet polymerization formula Fluorinated polymeric material, base layer material and core material are inorganic optical materials；Chinese patent 201510754780.3 is public A kind of composite plane optical waveguide that surface evanescent field strength is tunable opened includes:Leading layer and tuning layer, leading layer is by glass Substrate and the periodic multilayer film being coated with thereon are constituted, the liquid crystal layer and its substrate layer structure that tuning layer is effectively arranged by one layer At；Leading layer and tuning layer overlap up and down constitutes composite plane waveguide；A kind of heat disclosed in Chinese patent 201510385994.8 Non-sensitive type planar optical waveguide includes basal layer and sandwich layer, and sandwich layer is formed on basal layer, further includes being coated on the sandwich layer four The top covering in week, top covering material includes ultraviolet polymerization formula fluorinated polymeric material, and base layer material and core material are nothings Machine optical material；A kind of multiple-quantum well waveguide butt-coupling method disclosed in Chinese patent 201110458024.8 includes：A, in N Type substrate last time the first multi-quantum pit structure of extension, first multi-quantum pit structure include the first lower waveguide layer, more than first Ducting layer on quantum well layer and first；B, after deielectric-coating to be deposited, mask lithography is carried out, removing using three step etching methods needs to carry out The waveguide portion of the first area of secondary epitaxy；The deielectric-coating is silica or silicon nitride；The three step etchings method is： Successively use RIE dry etching, non-selective wet corrosion and selective wet etching to needing to carry out the of secondary epitaxy The waveguide portion in one region is etched；C, epitaxial wafer is placed in metal organic chemical vapor deposition equipment and is carried out at high warm Reason；The temperature of the high-temperature heat treatment is 680 degrees Celsius, and the time is 15 minutes；D, two Multiple-quantum of secondary epitaxy growth regulation is carried out Well structure, second multi-quantum pit structure, generation have the second lower waveguide layer, ducting layer on the second multiple quantum well layer and second； Optical waveguide is a kind of extremely important structure in optical signal transmission field, and most of optical devices require to transmit by optical waveguide The optical devices such as optical signal, such as AWG, photoswitch.Single-chip integration photon device integrates the device monolithic of at least two functions Together, it can be avoided the coupling loss between each function element, to simplify the coupling package of device.Deep ultraviolet band is being killed Bacterium, perspective identification, marine microorganism research, medical treatment etc. have a wide range of applications potentiality, so, the light wave of deep ultraviolet band It leads and is of great significance in terms of scientific research.Since UV energy is higher, many optical waveguide materials all absorb ultraviolet light, energy The material for being enough in transmission ultraviolet light is seldom, shorter based on ultraviolet band wavelength, and the size of ultraviolet single mode waveguide requires small, core packet Refringence is small, and process allowance is small, causes to make in technique difficult.Therefore, a kind of deep ultraviolet multi-quantum well waveguide of R & D design, Overcome Conventional UV single mode waveguide size small, the defects of core packet refringence is small, and light field locality is not strong and process allowance is small, has Good society and economic value, have a extensive future.

Summary of the invention：

The purpose of the utility model is to overcome disadvantage of the existing technology, a kind of deep ultraviolet multiple quantum wells of R & D design Waveguide prepares the multi-quantum well waveguide for having that size is small, transmission loss is low and is easy to make and integrate.

To achieve the goals above, the utility model relates to the main structure of deep ultraviolet multi-quantum well waveguide include lower guarantor Sheath, substrate layer, sandwich layer, clad and up-protective layer；The upper surface of the lower protective layer of rectangular plate-like structure is provided with rectangular block The substrate layer of shape structure, the sandwich layer for being provided centrally with rectangular block shape structure of substrate layer, the front of sandwich layer, rear portion, left part, right part Clad is wrapped with top, the upper surface of clad is provided with the up-protective layer of rectangular plate-like structure；The main structure of sandwich layer Including low-index layer and high refractive index layer, low-index layer and high refractive index layer are according to one layer of low-index layer, one layer high folding The sequence for penetrating rate layer is arranged alternately from the bottom to top, is finally bound by one layer of low-index layer, and the number of plies of low-index layer is n, high The index layer number of plies is n-1.

The utility model compared with prior art, uses two or more combined material on substrate layer, raw Grow tall/the alternate low-index layer of low-refraction and high refractive index layer, then low-index layer and high refractive index layer are etched into square Shape restricted area is as sandwich layer, in the surrounding growth clad of sandwich layer, finally distinguishes in the bottom surface of substrate layer and the top surface of clad Following table sheath and up-protective layer are grown, the ultraviolet multi-quantum well waveguide of rectangular configuration is obtained, passes through design low-index layer and height The effective refractive index that the number of plies and thickness of index layer freely change sandwich layer is poor, provides flexibly for deep ultraviolet Quantum Well waveguide Mentality of designing, simple structure and production method；Its size is small, and transmission loss is low, is easily integrated, to depth in deep ultraviolet band UV absorption is smaller, can be as the raw material of various fiber waveguide devices.

Detailed description of the invention：

Fig. 1 is the agent structure schematic diagram of the utility model.

Fig. 2 is the flow diagram of the production method of the utility model.

Fig. 3 is the test result schematic diagram for the Y beam splitter that the utility model embodiment 1 is related to.

Fig. 4 is the process schematic of the production method for the deep ultraviolet multi-quantum well waveguide that the utility model embodiment 2 is related to.

Fig. 5 is the mode distributions figure of deep ultraviolet multi-quantum well waveguide prepared by the utility model embodiment 2.

Specific embodiment：

The utility model is described further by way of example and in conjunction with the accompanying drawings.

Embodiment 1：

The main structure for the deep ultraviolet multi-quantum well waveguide that the present embodiment is related to includes lower protective layer 1, substrate layer 2, sandwich layer 3, clad 4 and up-protective layer 5；The upper surface of the lower protective layer 1 of rectangular plate-like structure is provided with the substrate of rectangular block shape structure Layer 2, the sandwich layer 3 for being provided centrally with rectangular block shape structure of substrate layer 2, front, rear portion, left part, right part and the top of sandwich layer 3 are wrapped up in It is covered with clad 4, the upper surface of clad 4 is provided with the up-protective layer 5 of rectangular plate-like structure；The main structure of sandwich layer 3 includes Low-index layer 10 and high refractive index layer 20, low-index layer 10 and high refractive index layer 20 are according to one layer of low-index layer 10, and one The sequence of layer high refractive index layer 20 is arranged alternately from the bottom to top, is finally bound by one layer of low-index layer 10, low-index layer 10 The number of plies be n (n be integer) greater than 3,20 number of plies of high refractive index layer be n-1 (n is the integer greater than 3).

The lower protective layer 1 and up-protective layer 5 that the present embodiment is related to are polysilicon film or pure silicon film；Substrate layer 2, low-refraction The raw material of layer 10, high refractive index layer 20 and clad 4 is included in the lesser silica of the deep ultraviolet band absorption coefficient of light, fluorination Magnesium, calcirm-fluoride, magnesia, lanthanum fluoride, aluminium oxide and hafnium oxide；The effect of lower protective layer 1 and up-protective layer 5 is to prevent substrate layer 2, sandwich layer 3 and clad 4 make moist and are damaged；Low-index layer 10 and high refractive index layer 20 choose two or more combination The sandwich layer 3 of low-index layer 10 and the alternate rectangle of high refractive index layer 20 limitation plot structure, low refraction are etched into after Material growth The refractive index of rate layer 10 is lower than the refractive index of high refractive index layer 20, the refraction low with lowest level of the thickness of top layer's low-index layer 10 The thickness of rate layer 10 is identical, and the thickness of top layer's low-index layer 10 and the thickness of lowest level low-index layer 10 are low with middle layer The thickness of index layer 10 is not identical.

The equivalent refractive index for the sandwich layer 3 that the present embodiment is related to is according to low-index layer 10 and 20 thickness of high refractive index layer and layer Several selections determines, the refringence and bending radius of deep ultraviolet multi-quantum well waveguide are controlled according to the equivalent refractive index of sandwich layer 3 And the size of the device based on the preparation of deep ultraviolet multi-quantum well waveguide, make the device of preparation be easier to integrate, as shown in Figure 3 Y beam splitter based on the production of deep ultraviolet multi-quantum well waveguide can stablize transmission ultraviolet light wave at 225nm wavelength, and at Y points Energy is divided into two at branch.

Embodiment 2：

The technical process of the production method for the deep ultraviolet multi-quantum well waveguide that the present embodiment is related to includes preparing substrate layer, system Standby sandwich layer prepares clad and prepares protective layer totally four steps：

(1) substrate layer is prepared：Raw material substrate, is cut into the size of setting by the raw material for choosing substrate layer 2, is completed The preparation of substrate layer 2；

(2) sandwich layer is prepared：Using plasma reinforced chemical vapour deposition method (Plasma Enhanced Chemical Vapor Deposition), Low Pressure Chemical Vapor Deposition (Low Pressure Chemical Vapor Deposition), Chemical vapour deposition technique (Chemical Vapor Deposition) or flame method (Flame Hydrolysis Method) exist The upper surface of substrate layer 2 is according to one layer of low-index layer 10, and alternating growth is low from the bottom to top for the sequence of one layer of high refractive index layer 20 Index layer 10 and high refractive index layer 20 are finally bound by one layer of low-index layer 10, and the number of plies of low-index layer 10 is 6, high 20 number of plies of index layer is 5, and low-index layer 10 and high refractive index layer 20 are etched rectangular restricted area using etching technics and tied The sandwich layer 3 of structure completes the preparation of sandwich layer 3；

(3) clad is prepared：Using plasma reinforced chemical vapour deposition method (Plasma Enhanced Chemical Vapor Deposition), Low Pressure Chemical Vapor Deposition (Low Pressure Chemical Vapor Deposition), Chemical vapour deposition technique (Chemical Vapor Deposition) or flame method (Flame Hydrolysis Method) exist Front, rear portion, left part, right part and the upper grown clad 4 of sandwich layer 3；

(4) protective layer is prepared：Using vapor deposition or silane thermal decomposition process substrate layer 1 bottom surface grow one layer of polysilicon film or Pure silicon film as lower protective layer 1, clad 4 one layer of polysilicon film of grown on top or pure silicon film as up-protective layer 5, use Polysilicon not or silicon fiml is oxidized to silica, or is not directly grown one layer of metal in the bottom surface of substrate layer 1 by thermal oxidation technology Film as lower protective layer 1, clad 4 grown on top layer of metal film as up-protective layer 5, complete the preparation of protective layer, Obtain deep ultraviolet multi-quantum well waveguide.

Deep ultraviolet multi-quantum well waveguide manufactured in the present embodiment is rectangular waveguide, the size of rectangular waveguide according to substrate layer 2, The raw material of low-index layer 10, high refractive index layer 20 and clad 4 chooses and low-index layer 10 and high refractive index layer 20 Thickness and the number of plies, which are chosen, to be determined.

Claims (1)

1. a kind of deep ultraviolet multi-quantum well waveguide, it is characterised in that main structure includes lower protective layer, substrate layer, sandwich layer, cladding Layer and up-protective layer；The upper surface of the lower protective layer of rectangular plate-like structure is provided with the substrate layer of rectangular block shape structure, substrate layer The sandwich layer for being provided centrally with rectangular block shape structure, front, rear portion, left part, right part and the top of sandwich layer wrapped clad, wraps The upper surface of coating is provided with the up-protective layer of rectangular plate-like structure；The main structure of sandwich layer includes low-index layer and high refraction Rate layer, low-index layer and high refractive index layer are handed over from the bottom to top according to one layer of low-index layer, the sequence of one layer of high refractive index layer It for setting, is finally bound by one layer of low-index layer, the number of plies of low-index layer is n, and the high refractive index layer number of plies is n-1.