Tunable semiconductor saturable absorption mirror based on quantum stark effect

Abstract

The utility model belongs to the technical field of semiconductors, and relates to a tunable semiconductor saturable absorption mirror based on the quantum stark effect. The semiconductor saturable absorption mirror comprises a back electrode layer; the substrate insulating layer is arranged on the back electrode layer; the substrate layer is arranged on the base insulating layer; the spectrum tuning unit array is arranged on the substrate layer; wherein the spectrum tuning unit array comprises a plurality of spectrum tuning units which are arranged at intervals, and each spectrum tuning unit comprises a Bragg reflection layer, a quantum well absorption layer, a transparent insulation layer and a transparent electrode layer which are sequentially arranged from bottom to top. According to the utility model, the wavelength-tunable semiconductor saturable absorber mirror can be realized through the quantum stark effect, the application scene of the semiconductor saturable absorber mirror is enriched, and the performance and reliability of the semiconductor saturable absorber mirror in the ultrafast laser technology are improved.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, and in particular relates to a tunable semiconductor saturable absorber mirror based on the quantum Stark effect. Background Technology

[0002] With the rapid development of fields such as fiber optic communication, laser processing, laser medicine, and lidar, the demand for high-performance ultrafast pulsed lasers is increasing. Passive mode-locked lasers, due to their advantages such as simple structure, stable performance, low mode-locking threshold, short response time, and narrow output pulse, have become an important development direction for ultrafast laser technology. Saturable absorbers (SESAMs), as the core component of passive mode-locked lasers, have become the most widely used passive mode-locking element due to their mature semiconductor fabrication process and excellent nonlinear optical properties.

[0003] In recent years, quantum well materials have gradually become a research hotspot due to their unique quantum effects and tunable electroabsorption properties. Quantum well structures are composed of semiconductor materials with different band gaps, in which charge carriers are localized in one dimension, exhibiting optical properties different from bulk materials. When an external electric field is applied perpendicularly to the quantum well, a quantum-confined Stark effect with a redshift at the absorption edge occurs, providing a theoretical basis for achieving dynamic wavelength control.

[0004] In fields such as multi-wavelength laser systems, optical communication networks, and multispectral imaging, there is a need for SESAM devices that can flexibly adjust the output wavelength. However, existing SESAM devices can only provide laser output of a single wavelength, which cannot meet the increasingly diverse and complex application requirements. Summary of the Invention

[0005] This invention provides a tunable semiconductor saturable absorber mirror based on the quantum Stark effect, which at least solves the problem that SESAM devices in related technologies can only provide laser output of a single wavelength and cannot meet the needs of increasingly diverse and complex application scenarios.

[0006] According to an embodiment of the present invention, a tunable semiconductor saturable absorber mirror based on the quantum Stark effect is provided, characterized in that the semiconductor saturable absorber mirror comprises:

[0007] Back electrode layer;

[0008] A substrate insulating layer is disposed on the back electrode layer;

[0009] A substrate layer is disposed on the insulating layer of the substrate;

[0010] An array of spectral tuning units is disposed on the substrate layer;

[0011] The spectral tuning unit array includes multiple spectral tuning units spaced apart, and each spectral tuning unit includes a Bragg reflection layer, a quantum well absorption layer, a transparent insulating layer, and a transparent electrode layer arranged sequentially from bottom to top.

[0012] In one embodiment of the present invention, the spectral tuning unit array includes at least three spectral tuning units.

[0013] In one embodiment of the present invention, the back electrode layer includes a metal electrode layer and an adhesive layer, wherein the adhesive layer is used to connect the metal electrode layer and the substrate insulating layer.

[0014] In one embodiment of this utility model, the material of the metal electrode layer is one or more of Au, Ag, Cu, and Al, and the thickness of the metal electrode layer is 100nm to 1000nm; the material of the adhesive layer is Ti, Ni, or Cr, and the thickness of the adhesive layer is 3nm to 20nm.

[0015] In one embodiment of this utility model, the material of the substrate insulating layer is SiO2, Si3N4, Al2O3 or Hf2O3, and the thickness of the substrate insulating layer is 100nm to 500nm.

[0016] In one embodiment of this utility model, the substrate is a gallium arsenide substrate or an indium phosphide substrate, and the thickness of the substrate is 300μm to 600μm.

[0017] In one embodiment of the present invention, the Bragg reflector layer includes multiple Bragg mirror groups, and each Bragg mirror group includes two thin film layers with different refractive indices.

[0018] The number of Bragg mirror groups is between 10 and 30.

[0019] In one embodiment of this utility model, the quantum well absorption layer is a gallium arsenide quantum well or an indium phosphide quantum well.

[0020] In one embodiment of this utility model, the transparent insulating layer is made of one or more of SiO2, Si3N4, Al2O3, and Hf2O3, and the thickness of the transparent insulating layer is 100nm to 500nm.

[0021] In one embodiment of this invention, the transparent electrode layer is made of an ITO electrode and a conductive polymer electrode, and the thickness of the transparent electrode layer is 30 nm to 200 nm.

[0022] The beneficial effects of this utility model embodiment:

[0023] The semiconductor saturable absorber mirror (SESAM) provided in this embodiment achieves wavelength tunability, enhancing its application flexibility and applicability in ultrafast laser technology. Specifically, this invention utilizes an array of spectral tuning units disposed above a substrate layer. Each spectral tuning unit includes a Bragg reflector layer, a quantum well absorption layer, a transparent insulating layer, and a transparent electrode layer, with each spectral tuning unit being independent and spaced apart. Based on this structure, different voltages can be applied to each spectral tuning unit, thereby creating external electric fields of varying intensities within the quantum well absorption layer. According to the quantum Stark effect, the application of the external electric field causes the energy band of the quantum well absorption layer to tilt, resulting in a redshift of the absorption edge, thus achieving wavelength adjustment in different regions.

[0024] By incorporating at least three spectral tuning units, this invention can provide multiple independently adjustable wavelength outputs, meeting the needs of complex applications such as multi-wavelength laser systems, optical communication networks, and multispectral imaging. Furthermore, the back electrode layer provides a stable voltage input and possesses excellent thermal conductivity, effectively dissipating the heat generated during SESAM operation and ensuring the device's stability during long-term operation.

[0025] In summary, this invention realizes a wavelength-tunable SESAM device through the quantum Stark effect, which not only enriches the application scenarios of SESAM, but also improves its performance and reliability in ultrafast laser technology.

[0026] Details of one or more embodiments of the present invention are set forth in the following drawings and description, so that other features, objects and advantages of the present invention will be more readily understood. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a tunable semiconductor saturable absorber mirror based on the quantum Stark effect, provided for an embodiment of this utility model.

[0029] Figure 2 A schematic diagram illustrating the working principle of a tunable semiconductor saturable absorber mirror based on the quantum Stark effect, provided for an embodiment of this utility model.

[0030] Figure 3This is a schematic diagram of a quantum well band structure without an external electric field, provided as an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of a quantum well band structure after applying an external electric field, provided as an embodiment of the present invention.

[0032] In the figure: 1. Back electrode layer; 2. Substrate insulating layer; 3. Substrate layer; 4. Bragg reflector layer; 5. Quantum well absorber layer; 6. Transparent insulating layer; 7. Transparent electrode layer. Detailed Implementation

[0033] Embodiments of this embodiment will now be described in more detail with reference to the accompanying drawings. While some embodiments of this embodiment are shown in the drawings, it should be understood that this embodiment can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this embodiment. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this embodiment.

[0034] In several key areas of modern technology, such as fiber optic communication, laser processing, laser medicine, and lidar, the demand for high-performance ultrafast pulsed lasers is growing. Passive mode-locked lasers, with their significant advantages such as simple structure, stable performance, low mode-locking threshold, short response time, and narrow output pulses, have become one of the core development directions of ultrafast laser technology. Among them, semiconductor saturable absorber mirrors (SESAMs), as key components of passive mode-locked lasers, have become the most widely used passive mode-locking technology due to their mature semiconductor fabrication process and excellent nonlinear optical properties.

[0035] In recent years, quantum well materials have gradually become a research hotspot due to their unique quantum effects and tunable electroabsorption properties. Quantum well structures are composed of semiconductor materials with different band gaps, in which charge carriers are localized in one dimension, exhibiting optical properties different from bulk materials. When an external electric field is applied perpendicularly to the quantum well, a quantum-confined Stark effect with a redshift at the absorption edge occurs, providing a theoretical basis for achieving dynamic wavelength control.

[0036] However, most existing SESAM devices can only provide laser output of a single wavelength, which is insufficient to meet the increasingly diverse and complex application requirements. For example, in fields such as multi-wavelength laser systems, optical communication networks, and multispectral imaging, SESAM devices capable of flexibly adjusting the output wavelength are needed. Therefore, developing a wavelength-tunable SESAM based on the quantum Stark effect can not only enrich the application scenarios of SESAM but also provide a new technical means for the development of ultrafast laser technology.

[0037] Figure 1 This is a schematic diagram of a tunable semiconductor saturable absorber mirror based on the quantum Stark effect, provided as an embodiment of the present invention. Figure 1 As shown, the semiconductor saturable absorber mirror provided in this embodiment of the present invention includes a back electrode layer 1, a substrate insulating layer 2, a substrate layer 3, and a spectral tuning unit array.

[0038] Among them, the back electrode layer 1 serves as the base layer of the entire semiconductor saturable absorber mirror, providing current conduction and heat conduction functions; the substrate insulating layer 2 is disposed on the back electrode layer 1, which can prevent electrical interference between the back electrode layer 1 and the upper structure, while isolating the thermal effect on the optical layer; the substrate layer 3 is disposed on the substrate insulating layer 2, which serves as the core structure supporting the semiconductor saturable absorber mirror, and is used to support the upper electrode and optical functional components.

[0039] The spectral tuning unit array is disposed on the substrate layer 3. Specifically, the spectral tuning unit array includes multiple spectral tuning units arranged at intervals, and each spectral tuning unit includes a Bragg reflective layer 4, a quantum well absorption layer 5, a transparent insulating layer 6, and a transparent electrode layer 7 arranged sequentially from bottom to top.

[0040] In this embodiment, the multi-layer structure of the Bragg reflector layer 4 can improve the reflectivity of light and has a high efficiency in reflecting light of a specific wavelength. It can work with the quantum well absorption layer 5 to achieve optical gain control. The quantum well absorption layer 5, as the core absorption component, can tune its absorption characteristics through the quantum Stark effect. The transparent insulating layer 6 can improve the light transmittance and isolate the electric field. The transparent electrode layer 7 can ensure uniform current distribution and support optical output.

[0041] In one optional embodiment, the spectral tuning unit array includes at least three spectral tuning units. In practical applications, each spectral tuning unit can independently control the applied electric field, achieving wavelength regional modulation by adjusting the voltage of each region. Based on the above structure, the wavelength tunability of the device can be enhanced, thereby meeting the complex requirements of multi-wavelength lasers.

[0042] In this embodiment, the back electrode layer 1 includes a metal electrode layer and an adhesive layer. The adhesive layer connects the metal electrode layer and the substrate insulating layer 2. The metal electrode layer provides electrical and thermal conductivity, which is fundamental to the stable operation of the entire device. The adhesive layer improves the adhesion between the metal electrode layer and the insulating layer, ensuring mechanical and thermal stability.

[0043] Optionally, the metal electrode layer can be made of one or more of Au, Ag, Cu, and Al, and its thickness can range from 100 nm to 1000 nm. The adhesive layer can be made of Ti, Ni, or Cr, and its thickness can range from 3 nm to 20 nm. In practical applications, thicker metal electrodes help dissipate heat and improve device lifespan, while thinner adhesive layers provide good connectivity and prevent interlayer separation caused by thermal expansion.

[0044] In this embodiment, the material of the substrate insulating layer 2 can be SiO2, Si3N4, Al2O3, or Hf2O3, and the thickness of the substrate insulating layer 2 can be 100nm to 500nm. Choosing a thickness between 100nm and 500nm optimizes the balance between electric field isolation and mechanical support.

[0045] In this embodiment, substrate 3 is a gallium arsenide substrate or an indium phosphide substrate, and the thickness of substrate 3 is 300 μm to 600 μm. Gallium arsenide substrates have excellent optical and electronic properties, making them suitable for laser applications; while indium phosphide substrates exhibit excellent performance over a longer wavelength range.

[0046] In this embodiment, the Bragg reflector layer 4 includes multiple Bragg mirror groups, each group comprising two thin film layers with different refractive indices. The number of Bragg mirror groups ranges from 10 to 30. In practical applications, the two thin film layers with different refractive indices in each Bragg mirror group can create an interference effect to improve reflectivity. The number of Bragg mirror groups (10-30 groups) determines the reflection spectral range and efficiency, and can be determined based on the actual application wavelength range.

[0047] In this embodiment, the quantum well absorption layer 5 is a gallium arsenide quantum well or an indium phosphide quantum well. In practical applications, gallium arsenide quantum wells are suitable for lasers in the range of 850 nm to 1 μm, while indium phosphide quantum wells are suitable for lasers in the range of 1.3 μm to 1.55 μm.

[0048] In this embodiment, the material of the transparent insulating layer 6 is one or more of SiO2, Si3N4, Al2O3, and Hf2O3, and the thickness of the transparent insulating layer 6 is 100nm to 500nm.

[0049] In this embodiment, the material of the transparent electrode layer 7 includes: ITO electrode and conductive polymer electrode, and the thickness of the transparent electrode layer 7 is 30nm to 200nm.

[0050] In one optional embodiment, the spacing between the spectral tuning units can be specifically set according to the specific implementation requirements. The main purpose is to avoid electric field interference through appropriate spacing, while ensuring that the overall size of the SESAM device remains within the millimeter range. Specifically, the spacing between the transparent electrode units can be set to 50 μm to 500 μm, preferably 100 μm to 300 μm. Within this range, it is possible to effectively avoid the impact of electric field interference on the independent control of each transparent electrode unit, while ensuring a compact layout of the transparent electrode array, so that the overall device size meets application requirements, and facilitates the implementation of the manufacturing process.

[0051] Figure 2 This diagram illustrates the working principle of a tunable semiconductor saturable absorber mirror based on the quantum Stark effect, as provided in an embodiment of this utility model. Figure 2 As shown, the semiconductor saturable absorber mirror provided in this embodiment can utilize an array of spectral tuning units to generate external electric fields of varying intensities by applying different voltages to different spectral tuning units, thereby producing regionally differentiated band structure changes within the quantum well absorption layer. The core of this principle is based on the quantum Stark effect.

[0052] Specifically, the spectral tuning unit array includes spectral tuning units in three regions: left, middle, and right. In this embodiment, the spectral tuning unit in the left region has no voltage applied (the electric field strength is zero); the spectral tuning unit in the middle region is equipped with a voltage V1, generating an external electric field of a certain intensity; and the spectral tuning unit in the right region is equipped with a higher voltage V2, forming a stronger external electric field.

[0053] The different applied voltages create different external electric field strengths among the various spectral tuning units, resulting in differences in the band structure of the quantum well material in these regions.

[0054] Quantum well absorber materials are "potential well" structures in which electrons and holes are confined to a two-dimensional plane. When an external electric field is applied perpendicularly to the quantum well absorber, it affects the wave function distribution of electrons and holes, resulting in the following changes:

[0055] Band tilt: Under the influence of an external electric field, the energy bands inside the quantum well barrier tilt, reducing the energy difference between the conduction band bottom and the valence band top, thus increasing the effective band gap (E). g (narrowing)

[0056] Absorption edge redshift: The decrease in bandgap directly leads to an increase in the wavelength of the emission peak or absorption edge, i.e., a redshift occurs. The magnitude of the redshift (Δλ) is closely related to the applied voltage (electric field strength); the higher the voltage, the greater the redshift.

[0057] In the three regions, the left region, without an electric field, maintains the original wavelength λ. In the middle region (where V1 is applied), the electric field red-shifts, and the emission wavelength becomes λ1 = λ + Δλ1. In the right region (where V2 is applied), the electric field red-shifts even further, and the emission wavelength becomes λ2 = λ + Δλ2, where Δλ2 > Δλ1.

[0058] Based on the above description, each spectral tuning unit emits a different wavelength, thus achieving multi-wavelength output in a single device. For example, the left, center, and right regions emit light at wavelengths λ, λ1, and λ2, respectively.

[0059] In practical applications, the wavelength redshift can be flexibly changed by adjusting the voltage of the spectral tuning unit. This characteristic allows the device to actively control the emission wavelength according to requirements, making it suitable for complex optical scenarios. Optionally, since the redshift (Δλ) is continuously adjustable, precise wavelength control can be achieved, thus adapting it to various fields such as fiber optic communication and laser medicine.

[0060] The semiconductor saturable absorber mirror provided in this embodiment achieves multi-wavelength zoned output through zoned electric field control, expanding the functionality of SESAM. The wavelength tuning range is determined by the applied electric field, exhibiting wide adaptability. Furthermore, compared to traditional single-wavelength SESAMs, the semiconductor saturable absorber mirror provided in this embodiment significantly enhances device functionality without increasing complexity through the design of transparent electrode arrays and quantum well materials.

[0061] Figure 3 This is a schematic diagram of a quantum well band structure without an external electric field, provided as an embodiment of the present invention. Figure 3 As shown, in the absence of an external electric field, the energy difference (Eg0) between the conduction band bottom and the valence band top is the band gap of the quantum well. Because the movement of electrons and holes in the quantum well is spatially confined, discrete quantized energy levels are formed within the conduction and valence bands. Figure 3 The energy levels are represented by horizontal dashed lines. These energy levels correspond to different energy states of electrons and holes, influencing transition absorption and luminescence properties in optical behavior. In this state, the energy level distribution of the quantum well depends only on the properties of the material itself and the quantum well structural parameters, and is not affected by external factors, thus exhibiting an inherent emission wavelength λ.

[0062] Figure 4 This is a schematic diagram of a quantum well band structure after applying an external electric field, provided as an embodiment of the present invention. Figure 4As shown, when an external electric field is applied perpendicularly to the quantum well, a significant change occurs in the energy band structure. The electric field tilts the conduction and valence bands, disrupting the original symmetrical band structure. The energy difference between the bottom of the conduction band and the top of the valence band decreases, and the new band gap, Eg1, is smaller than the original band gap, Eg0. This change triggers alterations in the electron-hole transition behavior within the quantum well, resulting in a redshift of the quantum well's emission or absorption wavelength. Specifically, the emission wavelength increases from λ to λ+Δλ, and the magnitude of the redshift Δλ is proportional to the strength of the external electric field. In this process, the external electric field modulates the band shape and the position of the quantized energy levels by altering the potential distribution within the quantum well, thereby achieving dynamic control over the optical properties.

[0063] Figure 3 and Figure 4 This demonstrates the physical essence of the quantum Stark effect. By manipulating an external electric field, the shape and energy level structure of the conduction and valence bands in a quantum well change, thereby achieving adjustment of the bandgap and tunability of the optical response wavelength. This effect provides a flexible functional design basis for optical devices such as semiconductor saturable absorber mirrors.

[0064] Based on the above principles, the semiconductor saturable absorber mirror provided in this embodiment fully utilizes the characteristics of the quantum Stark effect, realizing wavelength tunability in a single device, and providing a highly flexible and efficient solution for laser technology applications.

[0065] In an optional embodiment, the semiconductor saturable absorber mirror provided by this invention can be prepared based on the following method:

[0066] First, a suitable substrate material is selected as the preparation substrate. The substrate can be gallium arsenide (GaAs) or indium phosphide (InP), with a thickness controlled between 300 μm and 600 μm. The substrate is thoroughly cleaned to remove surface impurities to ensure the bonding quality of subsequent deposited layers. Cleaning can be performed using an ultrasonic cleaner in conjunction with solvents such as deionized water and isopropanol.

[0067] A substrate insulating layer 2 is deposited beneath the substrate to isolate electrical interference between the substrate and the back electrode. The substrate insulating layer 2 can be made of one or more of SiO2, Si3N4, Al2O3, or Hf2O3, with a thickness controlled between 100 nm and 500 nm. Chemical vapor deposition (CVD) or atomic layer deposition (ALD) is preferred to ensure excellent uniformity and density of the insulating layer.

[0068] Then, an adhesion layer and a metal electrode layer are sequentially deposited on the substrate insulating layer 2 by electron beam evaporation or sputtering deposition. The adhesion layer material can be Ti, Ni, or Cr, with a thickness between 3 nm and 20 nm, to enhance the adhesion between the metal electrode and the substrate insulating layer 2. The metal electrode layer material can be one or more of Au, Ag, Cu, or Al, with a thickness controlled between 100 nm and 1000 nm, preferably 500 nm to 1000 nm, to simultaneously achieve good electrical and thermal conductivity.

[0069] A Bragg reflector layer 4 is fabricated on top of the substrate. The Bragg reflector layer 4 consists of multiple pairs of thin films with alternating high and low refractive indices, with the thickness of each pair precisely controlled to match the optical interference conditions of the target wavelength. The specific material of the Bragg reflector layer 4 can be two of AlAs, GaAs, InAs, AlGaAs, AlInAs, InGaA, InP, or GaInAsP, depending on the design. It is epitaxially obtained using MOCVD or MBE techniques. Ultimately, 10 to 30 pairs of Bragg reflectors are formed, ensuring high reflectivity within the target wavelength range.

[0070] A quantum well absorption layer 5 is deposited on the Bragg reflector layer 4. Gallium arsenide or indium phosphide quantum well structures are grown using molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD). The thickness and number of quantum wells need to be designed according to the target wavelength tuning range to ensure that they exhibit good quantum Stark effect under different electric fields.

[0071] A transparent insulating layer 6 is deposited on the quantum well absorber layer 5. The material can be SiO2, Si3N4, Al2O3, or Hf2O3, and the thickness ranges from 100 nm to 500 nm. The transparent insulating layer 6 is preferably prepared using the ALD process to ensure that the film has high optical transmittance and uniformity.

[0072] A transparent electrode layer 7 is deposited on the transparent insulating layer 6. The transparent electrode material can be ITO (indium tin oxide) or a conductive polymer, and its thickness is controlled between 30 nm and 200 nm. The transparent electrode layer 7 can be deposited by magnetron sputtering to ensure the conductivity and optical transparency of the electrode.

[0073] The spacing between the spectral tuning units is fabricated using semiconductor etching technology. Photolithography is used to define the etching regions, and dry etching (such as reactive ion etching, RIE) is used to remove portions of the transparent insulating layer 6 and the transparent electrode layer 7, forming multiple independent spectral tuning units. The spacing width is designed according to the electric field distribution requirements to ensure that no electrical short circuits occur between different electrode units, while optimizing the electric field modulation effect.

[0074] Finally, the spectral tuning units are connected by wires to form a spectral tuning unit array. The device is then packaged to protect its surface from environmental influences. During packaging, it is essential to ensure both the transparency of the optical output window and mechanical protection.

[0075] The fabricated semiconductor saturable absorber mirror achieves wavelength tunability by applying different voltages to different spectral tuning units to realize the optical response differences of the quantum well absorption layer 5 in different regions.

[0076] It should be noted that the term "comprising" and its variations used in the embodiments of this utility model are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of this utility model are illustrative and not restrictive. Those skilled in the art should understand that, unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0077] The steps described in the method embodiments provided by this utility model can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of this utility model is not limited in this respect.

[0078] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0079] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the appended claims.

Claims

1. A tunable semiconductor saturable absorber mirror based on the quantum Stark effect, characterized in that, The semiconductor saturable absorber mirror includes: Back electrode layer (1); A substrate insulating layer (2) is disposed on the back electrode layer (1); A substrate layer (3) is disposed on the substrate insulating layer (2); An array of spectral tuning units is disposed on the substrate layer (3); The spectral tuning unit array includes multiple spectral tuning units spaced apart. Each spectral tuning unit includes a Bragg reflection layer (4), a quantum well absorption layer (5), a transparent insulating layer (6), and a transparent electrode layer (7) arranged sequentially from bottom to top.

2. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The spectral tuning unit array includes at least three spectral tuning units.

3. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The back electrode layer (1) includes a metal electrode layer and an adhesive layer, wherein the adhesive layer is used to connect the metal electrode layer and the substrate insulating layer (2).

4. The semiconductor saturable absorber mirror according to claim 3, characterized in that, The thickness of the metal electrode layer is 100nm~1000nm; the material of the adhesive layer is Ti, Ni or Cr, and the thickness of the adhesive layer is 3nm~20nm.

5. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The material of the substrate insulating layer (2) is SiO2, Si3N4, Al2O3 or Hf2O3, and the thickness of the substrate insulating layer (2) is 100nm~500nm.

6. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The substrate (3) is a gallium arsenide substrate or an indium phosphide substrate, and the thickness of the substrate (3) is 300μm~600μm.

7. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The Bragg reflector layer (4) includes multiple Bragg reflector groups, and each Bragg reflector group includes two thin film layers with different refractive indices. The number of Bragg mirror groups is between 10 and 30.

8. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The quantum well absorption layer (5) is a gallium arsenide quantum well or an indium phosphide quantum well.

9. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The thickness of the transparent insulating layer (6) is 100nm~500nm.

10. The semiconductor saturable absorber mirror according to claim 1, characterized in that, The transparent electrode layer (7) is made of ITO electrode and conductive polymer electrode, and the thickness of the transparent electrode layer (7) is 30nm~200nm.

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