Semiconductor laser emitter and method of obtaining its power consumption

Abstract

The application provides a semiconductor laser emitter, characterized in that it comprises a cathode and an anode, and a first region and a second region; the first region comprises a capacitor, an inductor and a resistor; the second region comprises a capacitor, a power consumption module and an output power module; through the design, the DBR power consumption, the DBR resistance and the power consumption caused by carrier leakage of the semiconductor laser emitter can be determined.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, in particular to a semiconductor laser emitter and a method for obtaining the laser power consumption. BACKGROUND

[0002] Semiconductor laser, due to its excellent controllable performance, and very easy to realize the array type of integrated design, is more and more used in various detection processes, through the control of voltage and other characteristics, the adjustment of laser parameters can also be more convenient, which is very advantageous to the whole system. Semiconductor laser refers to the laser with semiconductor material as working substance, also known as semiconductor laser diode (LD), which is developed in the 1960s. The working substance of semiconductor laser has dozens of kinds, such as gallium arsenide (GaAs), cadmium sulfide (CdS) and so on. The main excitation modes include electric injection, optical pumping and high-energy electron beam excitation. The advantages of semiconductor laser mainly include the following aspects: 1) small size and light weight; 2) injectable excitation: only a few volts of voltage injection of milliamperes of current can drive it. Except for the power supply device, no other excitation equipment and parts are needed. The electric power is directly converted into optical power, and the energy efficiency is high. 3) wide wavelength range: by properly selecting materials and alloys, laser with any wavelength in a wide wavelength range of infrared and visible light can be realized. 4) direct modulation: by superimposing signals on the driving current, the oscillation intensity, frequency and phase can be modulated in the range of direct current to G hertz. 5) high coherence: single transverse mode laser can obtain high spatial coherence of output light. Stable single longitudinal mode oscillation can be obtained in distributed feedback (DFB) and distributed Bragg reflection (DBR) lasers, and high temporal coherence can be obtained.

[0003] At present, one of the most commonly used semiconductor lasers is surface emitting semiconductor laser, which has many advantages compared with traditional edge emitting semiconductor laser. Among the surface emitting semiconductor lasers, vertical cavity surface emitting laser (VCSEL) has low threshold, circular beam, easy coupling and two-dimensional integration, and has the advantages of high side mode suppression ratio, low threshold, small size, easy integration and high output power. It has become a hot spot in the field of optoelectronics. In the optical fiber communication system, long wavelength vertical cavity surface emitting laser source with dynamic single mode operation is an indispensable key component. It is mainly used in medium and long distance high speed data communication and optical interconnection, optical parallel processing, optical recognition system, and has important application in metropolitan area network and wide area network.

[0004] The basic structure of vertical cavity surface emitting laser (VCSEL) is as follows Figure 1As shown, including the upper and lower distributed Bragg reflector (DBR), oxidation limited hole, multi-quantum well active region and ohmic contact electrode. Quantum well active region between n-type doped and p-type doped DBR. DBR mirror has a reflectivity greater than 99%, by high and low refractive index medium or semiconductor material is alternately grown, the optical thickness of each layer of material is 1 / 4 of the laser wavelength. The optical thickness of the active region is an integer multiple of 1 / 2 (or (2k+1)*1 / 2) laser wavelength, by P-contact to the active region injection current and produce stimulated emission of photons in DBR back and forth is reflected and resonant amplification, thereby forming a laser. DBR has a very high series resistance, resulting in DBR heating is serious, heat spread out will cause the internal temperature of VCSEL increases, thereby affecting the device performance, such as threshold quantum efficiency, lasing wavelength change and so on. Therefore, to reduce the DBR resistance is one of the key problems to realize VCSEL room temperature continuous lasing. But in the prior art can not obtain the DBR power consumption and DBR resistance value, so there is an urgent need for a method to obtain the DBR power consumption and DBR resistance value. In order to test whether the process and other means to effectively reduce the DBR power consumption and DBR resistance value. SUMMARY

[0005] The purpose of the present application is to solve the problems caused by the inability to obtain the power consumption of the laser, especially the DBR power consumption and the DBR resistance value in the related art.

[0006] To achieve the above object, the technical scheme adopted by the embodiments of the present application is as follows:

[0007] The first aspect of the present application provides a semiconductor laser emitter, characterized by

[0008] It includes cathode and anode, and first region and second region.

[0009] The first region includes capacitance, inductance and resistance.

[0010] The second region includes capacitance, power consumption module and output power module.

[0011] Optionally, the capacitance of the first region is a parasitic capacitance.

[0012] Optionally, the resistance of the first region is a pad resistance.

[0013] Optionally, the resistance of the first region is a DBR resistance.

[0014] Optionally, the capacitance of the second region is a mesa capacitance.

[0015] Optionally, the capacitance of the second region is an active region capacitance.

[0016] Optionally, the power consumption module is a leakage power consumption module.

[0017] Optionally, the power consumption module is a non-radiative recombination power consumption module.

[0018] Optionally, the power consumption module is an internal optical loss module.

[0019] In a second aspect, the embodiments of the present application provide a method for determining the power consumption of a semiconductor laser emitter, applied to the semiconductor laser emitter of the first aspect, and the method comprises the following steps:

[0020] Three different current values are input to the anode and the cathode respectively;

[0021] Three voltage values corresponding to the three current values are obtained respectively;

[0022] The light output power under the three current values is measured respectively;

[0023] According to the relationship among the input power, the DBR power consumption, the carrier leakage power consumption and the output power, the DBR power consumption, the DBR resistance value and the power consumption value caused by the carrier leakage are determined.

[0024] The present application has the following advantages: the present application provides a semiconductor laser emitter, which comprises:

[0025] The cathode and the anode, and the first region and the second region;

[0026] The first region comprises a capacitance, an inductance and a resistance;

[0027] The second region comprises a capacitance, a power consumption module and an output power module, and through such a design, the DBR power consumption, the DBR resistance and the power consumption caused by the carrier leakage of the semiconductor laser emitter can be determined. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 A structural schematic diagram of a laser emitter provided in the prior art;

[0030] Figure 2 A structural schematic diagram of a laser emitter provided in the prior art;

[0031] Figure 3 An equivalent circuit diagram of a laser emitter provided in the embodiment of the present application;

[0032] Figure 4 A schematic diagram of injecting carriers in a quantum well of a laser emitter provided in the embodiment of the present application;

[0033] Figure 5 Another equivalent circuit diagram of a laser emitter provided in the embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application.

[0035] Figure 1For the prior art disclosed in an example diagram of a laser emitter, including a first electrode 101, the material of the first electrode can be gold (Au), germanium (Ge), silver (Ag), palladium (Pd), platinum (Pt), nickel (Ni), titanium (Ti), vanadium (V), tungsten (W), chromium (Cr), aluminum (Al), copper (Cu), zinc (Zn), tin (Sn) and indium (In) and the like, of course, not limited to metal materials, but also transparent electrodes formed by metal oxides, the first electrode is connected with a first DBR layer 102, wherein the first DBR layer 102 has a stacked structure in which low refractive index layers and high refractive index layers are alternately stacked. The low refractive index layer is, for example, a p-type AlX1Ga(1-X1)As (0X1<1) with an optical film thickness of λ / 4 (or (2k+1)*λ / 4). The high refractive index layer is, for example, a p-type AlX2Ga(1-X2)As (0≤X2X1) with an optical film thickness of λ / 4 (or (2k+1)*λ / 4). Here, this is only an example and is not a specific limitation on the implementation material. As long as the Bragg type structure is satisfied, in which the low refractive index and the high refractive index are alternately stacked, 107 is an oxidation limiting layer, which plays a role of limiting the generation of photons, so that the generated laser is more centered, and at the same time, it can reduce the refractive index of the resonator to increase the light loss of high-order transverse modes in this position and thus suppress oscillation, in which the strongest intensity can be obtained in the high-order transverse mode, thereby achieving better focusing effect, and the specific material is not limited here. 103 is the active region of the emitter, and the active region 103 has a quantum well structure in which quantum well layers with a thickness of 8 nm of undoped Al0.11As0.89GaAs quantum well layers and barrier layers with a thickness of 5 nm of undoped Al0.3Ga0.7As layers are alternately stacked. For example, the active region 103 is designed to have light emission with a wavelength of 780 nm, and the optical thickness of the active region 103 is an integer multiple of 1 / 2 of the laser wavelength. By injecting current into the active region through the P-contact first electrode 301, the generated excited radiation photons are reflected and resonantly amplified in the DBR, thereby forming a laser. The isolation layer formed by the undoped Al0.6Ga0.4As layer for forming a layer in the active region 3 includes a quantum well structure in the center thereof. The entire isolation layer has a film thickness as large as an integer multiple of λ / n r , where λ is the oscillation wavelength and n ris the refractive index of the medium, here, the implementation material, thickness, and the wavelength of the outgoing light, and other characteristics are only exemplary and not limited. The other end of the active region 103 is connected to a second DBR layer 104, which has a laminated structure in which low refractive index layers and high refractive index layers are alternately stacked. The low refractive index layer is, for example, n-type AlX3Ga(1-X3)As (0X3<1) with an optical film thickness of λ / 4 (or (2k+1)*λ / 4). λ represents the oscillation wavelength of the semiconductor laser 1. The high refractive index layer is, for example, n-type AlX4Ga(1-X4)As (0≤X4X3) with an optical film thickness of λ / 4 (or (2k+1)*λ / 4). Similar to the structure of the first DBR layer 102, the specific material is not limited here, and other materials can be used to form a Bragg structure in which low refractive index layers and high refractive index layers are alternately stacked. The DBR reflection region thus arranged can have a reflectivity of greater than 99%. The second DBR layer 104 can further be connected to a substrate layer 105, which is, for example, composed of a gallium arsenide (GaAs) substrate layer 105. The substrate layer 105 is made of a material that is transparent to the laminated structure (more specifically, a material that is transparent to the light generated by the active layer 103). The substrate layer 105 can be made of indium phosphide (InP), gallium nitride (GaN), indium gallium nitride (InGaN), sapphire, silicon (Si), silicon carbide (SiC), and the like. The material is not limited to the listed materials. The substrate layer 105 is further connected to a second electrode 106, which can be made of a material similar to the first electrode 101. By applying pressure to the electrodes, the VCSEL can be excited to operate.

[0036] Figure 2 A schematic diagram of a laser emitter structure in the prior art; a vertical external cavity surface emitting laser (VECSEL) can be divided into two types according to the driving mode, an optical pumped vertical external cavity surface emitting laser (OP-VECSEL) and an electrical pumped vertical external cavity surface emitting laser (VECSEL). Compared with the OP-VECSEL, the electrical pumped VECSEL has a more compact and smaller size. On the other hand, the VECSEL can directly convert electrical energy into laser output through electrical injection, and has a higher electrical-optical conversion efficiency. As shown in FIG. 1, the VECSEL is composed of a substrate layer 101, an active layer 102, a DBR layer 103, a second DBR layer 104, and a second electrode 105. Figure 2The diagram shows a VECSEL consisting of an N-type ohmic contact electrode 201, a substrate 202, an N-type doped distributed Bragg reflector (DBR) 203, a multi-quantum-well active region 204, a protective material layer 205, a P-type doped DBR 206, and an N-type ohmic contact electrode 207. The quantum-well active region is located between the N-type and P-type doped DBRs. The DBR reflector has a reflectivity greater than 99% and is epitaxially grown from alternating high- and low-refractive-index media or semiconductor materials, with each layer having an optical thickness of 1 / 4 of the laser wavelength. The optical thickness of the active region is an integer multiple of 1 / 2 of the laser wavelength. Current is injected into the active region through the P-contact, generating stimulated emission photons that are repeatedly reflected and resonantly amplified within the DBR, thus forming a laser beam.

[0037] Figure 3 An equivalent circuit diagram of a laser emitter provided for an embodiment of the present invention. Figure 3 As shown, 301 and 302 are the cathode and anode that inject current into the active region, respectively; 303 is the parasitic capacitance; 304 is the parasitic inductance; 305 is the pad resistor; 306 is the DBR resistor; 307 is the mesa capacitor; 308 is the active region capacitor; 309 is the carrier leakage power consumption module; 310 is the non-radiative composite power consumption module; 311 is the internal optical loss module; and 312 is the output power module. Figure 3 for Figure 2 The equivalent circuit diagram of the laser is shown. Figure 3 The power consumption of the VCSEL during operation includes Joule heating caused by the package lead resistor 305, Joule heating generated by the DBR resistor 306, and power consumption in the active region. The active region includes the output power of the emitted optical power module 312, the intracavity absorption power consumption of the internal optical loss module 311, the non-radiative recombination power consumption of the non-radiative recombination power consumption module 310, and the power consumption caused by the interband carrier leakage power consumption module 309. Figure 3 The region including 301 to 306 is the first region, which is the parasitic region of the chip, and the region including 307 to 312 is the second region, which is the active region of the VCSEL.

[0038] Figure 4 This is a schematic diagram of carrier injection in a quantum well of a laser emitter, provided as an embodiment of the present invention. Figure 4 The power of each part can be calculated.

[0039] P J =σ -1 ·I 2 =2.448mW (1)

[0040]

[0041]

[0042]

[0043]

[0044] Among them, E L (T) represents the quantum well band gap, E B (T) represents the quantum barrier band gap, η i (T) represents the internal quantum efficiency, I th (T) is the threshold current, α(T) is the light absorption coefficient; I is the driving current, ranging from 1 to 10 mA.

[0045] Formula (1) represents the total power, which can be obtained by adding up the power of each component; or it can be obtained by using the input current and voltage to get P=IV. Based on empirical formulas, under operating current and voltage conditions, the combined power consumption of optical absorption and non-radiative processes accounts for less than 10%, and these two items can be ignored in the calculation. Therefore, it is possible to... Figure 3 Simplify.

[0046] Figure 5 An equivalent circuit diagram of another laser emitter provided in an embodiment of the present invention, wherein... Figure 5 The equivalent circuit diagram is Figure 3 Simplification of circuit diagrams. Figure 3 The diagram is simplified, ignoring carrier recombination 310 and power consumption 311 absorbed by the internal optical cavity. The simplified result is as follows: Figure 5 The diagram shows a DBR resistor 503 in the first region, a carrier leakage power consumption 504 in the second region, and an output power 505. Figure 4 As shown, 501 and 502 are the cathode and anode injecting current into the active region, respectively; 503 is the DBR resistor; 504 is the carrier leakage power dissipation; and 505 is the output power. Figure 5 In the circuit shown, given the input currents I1, I2, and I3 for the anode 501 and cathode 502 respectively, the corresponding driving voltages V1, V2, and V3 can be obtained, and the optical power P can be measured. optl P opt2 P opt3 The power consumption of the resistor is the quadratic term of the current value, and the power consumption of the leakage electrons is the linear term of the current value. Solve the equations simultaneously.

[0047] I1V1=I1 2 R+I1′R′+P opt1 (6)

[0048] I²V² = I² 2 R+I2′R′+P opt2 (7)

[0049] I3V3 = I3 2 R + I3' R' + P opt3 (8)

[0050] I i ' + I D = I i (9)

[0051]

[0052] I' is the leakage current value, I D is the current flowing to the quantum well region. V D is the junction voltage, which can be obtained by measurement. The power consumption caused by carrier leakage is measured, and the DBR joule heat is solved by the equation group of formula (6)~formula (10). Through the above equivalent circuit of VCSE1, the power consumption caused by DBR resistance, DBR resistance value and carrier leakage power consumption can be accurately calculated. Through this method, it can be verified whether the process and other means effectively reduce the power consumption caused by DBR resistance, DBR resistance value and carrier leakage power consumption.

[0053] It should be noted that, in this text, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a…" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0054] The above descriptions are only the preferred embodiment of the present application, but not intended to limit the present application. Various modifications and changes can be carried out by those skilled in the art, which should be included in the scope of the present application so far as these modifications and changes do not deviate from the spirit and principle of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and once an item is defined in one drawing, it need not be further defined and explained in the subsequent drawings. The above descriptions are only the preferred embodiment of the present application, but not intended to limit the present application. Various modifications and changes can be carried out by those skilled in the art, which should be included in the scope of the present application so far as these modifications and changes do not deviate from the spirit and principle of the present application.

Claims

1. An equivalent circuit for a semiconductor laser emitter, characterized in that, include: Cathode and anode, and first region and second region; The first region includes: parasitic capacitance, parasitic inductance, pad resistor, and DBR resistor; the second region includes: mesa capacitor, active region capacitor, carrier leakage power dissipation module, and output power module; the first plate of the parasitic capacitor is connected to the anode, the second plate of the parasitic capacitor is connected to the cathode, one end of the parasitic inductance is connected to the anode, the other end of the parasitic inductance is connected to one end of the pad resistor, and the other end of the pad resistor is connected to one end of the DBR resistor; The platform capacitor, the active area capacitor, the power consumption module, and the output power module are connected in parallel. One end of the parallel connection is connected to the other end of the DBR resistor, and the other end of the parallel connection is connected to the cathode.

2. A method for determining the power consumption of a semiconductor laser emitter as described in claim 1, characterized in that, Includes the following steps: Three different current values ​​are input to the anode and cathode respectively; The three voltage values ​​corresponding to the three current values ​​were obtained respectively; The output power was measured at three different current values. Based on the relationship between input power equaling DBR power consumption, carrier leakage power consumption, and output power, the DBR power consumption, DBR resistance value, and power consumption caused by carrier leakage were determined.

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