Modulation grating Y-branch broadband tuning external cavity laser and equipment
By introducing a chalcogenide phase change material layer and additive vernier effect into a modulated grating Y-branch external cavity laser, combined with the Joule heating effect, rapid and precise multi-stage wavelength tuning was achieved, solving the problems of reduced lifetime and high power consumption caused by oxidation, and improving the performance and reliability of the laser.
Patent Information
- Application Number
- CN202511315897.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-15
- Publication Date
- 2026-01-09
AI Technical Summary
In existing modulated grating Y-branch broadband tuned external cavity lasers, oxidation after integrating phase change materials leads to a decrease in crystallization temperature, affecting the device's cycle life. At the same time, existing wavelength tuning schemes require continuous voltage bias, resulting in high power consumption.
By employing a chalcogenide phase change material layer, combined with the additive vernier effect and Joule heating effect, rapid and precise wavelength tuning of the external cavity laser is achieved, and low-loss coupling is realized through polymer waveguides to reduce power consumption.
This technology enables multi-stage wavelength tuning of external cavity lasers in a very short time, reducing power consumption, improving environmental adaptability and wavelength control accuracy, and extending device lifespan.
Smart Images
Figure CN121307630A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of laser technology, and more specifically, to a modulation grating Y-branch broadband tuned external cavity laser and its device. Background Technology
[0002] With the increasing demand for fast broadband tunable lasers, semiconductor lasers, due to their compact structure and small size, exhibit significant advantages over solid-state lasers and fiber lasers. Constructing a modulated grating Y-branch (MG-Y) broadband tunable laser as an external cavity semiconductor laser not only leverages the unique structural advantages of external cavity lasers to narrow the linewidth, but also, because the semiconductor optical amplifier (SOA) and external optical feedback elements are independent components, facilitate independent thermal management, reducing laser performance degradation caused by thermal effects.
[0003] By integrating phase change materials (PCMs) into modulation grating-based Y-branch broadband tunable external cavity lasers (MG-Y ECLs), ultrafast wavelength tuning can be achieved using nanosecond-level phase transitions. While PCMs offer numerous advantages in multi-stage tunable switches, this technology still faces several material science challenges in practical applications: for Ge-Te-based PCMs, oxidation significantly reduces their crystallization temperature, severely impacting the device's cycle life. Therefore, modulation grating-based Y-branch broadband tunable external cavity lasers require further investigation.
[0004] It should be noted that the above statements are only used to provide background information related to this application and do not necessarily constitute prior art. Summary of the Invention
[0005] This application provides a modulated grating Y-branch bandwidth-tuned external cavity laser, aiming to achieve rapid and precise multi-stage wavelength tuning of the external cavity laser in a very short time, while effectively reducing the power consumption of the external cavity laser.
[0006] In a first aspect, this application proposes a modulation grating Y-branch broadband tuned external cavity laser, comprising: a semiconductor optical amplifier (SOA) gain chip region; an external cavity waveguide region; and a coupling module, wherein the SOA gain chip region and the external cavity waveguide region are coupled together via the coupling module. The external cavity waveguide region includes: a waveguide structure; and a Y-branch sampling grating structure disposed on the surface of the waveguide structure. The Y-branch sampling grating structure has a first sampling grating and a second sampling grating. A chalcogenide phase change material layer is disposed on the surface of either the first or second sampling grating. The chalcogenide phase change material layer includes interconnected planar portions and protrusions, with the protrusions filling grooves in the first or second sampling grating. Therefore, thanks to the nanosecond-level phase switching speed of the chalcogenide phase change material layer, rapid and precise multi-stage wavelength tuning of the external cavity laser can be achieved in an extremely short time, making it applicable to applications requiring rapid tuning. Furthermore, the non-volatile nature of chalcogenide phase change materials allows them to maintain a stable state without the need for power supply after the state transition is completed, effectively reducing the power consumption of external cavity lasers and significantly improving their environmental adaptability and wavelength control accuracy, thus providing an ideal solution for the development of high-performance tunable external cavity lasers.
[0007] In addition, the modulation grating Y-branch broadband tuned external cavity laser according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the sulfide phase change material layer comprises antimony sulfide or antimony selenium. Sulfide phase change materials possess nanosecond-level phase change kinetics and are non-volatile, enabling stable and rapid wavelength tuning of external cavity lasers.
[0008] In some embodiments of this application, the Y-branch sampling grating structure includes a first interferometer arm and a second interferometer arm. The first interferometer arm has the first sampling grating on its surface, and the second interferometer arm has the second sampling grating on its surface. Thus, by independently adjusting the currents of the two interferometer arms, thereby changing their refractive index and reflection spectrum, different peak pairs can be aligned with each other.
[0009] In some embodiments of this application, the thickness of the planar portion of the chalcogenide phase change material layer is 5 nm to 10 nm. This results in a more uniform distribution of the electric and thermal fields, which helps to achieve a consistent and uniform phase transition, reducing the occurrence of a mixed state of partial crystallization and partial amorphization, thereby ensuring the stability and consistency of the external cavity laser's performance.
[0010] In some embodiments of this application, the sampling period of the first sampling grating is 466nm~469nm. This allows for adjustment of the spacing between the reflection peaks, control of the free spectral range, and thus setting the tuning range of the external cavity laser.
[0011] In some embodiments of this application, the duty cycle of the first sampling grating is 30% to 50%. This allows for precise control of the intensity distribution and uniformity of the reflection peak, thereby improving coupling efficiency.
[0012] In some embodiments of this application, the etching depth of the first sampling grating is 10nm~20nm. Therefore, while ensuring low loss, the modulation intensity of the sampling grating can be precisely controlled, thereby determining the reflectivity and bandwidth of each reflection peak.
[0013] In some embodiments of this application, the sampling period of the second sampling grating is 476nm~478nm. This allows for adjustment of the spacing between the reflection peaks, control of the free spectral range, and thus setting the tuning range of the external cavity laser.
[0014] In some embodiments of this application, the duty cycle of the second sampling grating is 30% to 50%. This allows for precise control of the intensity distribution and uniformity of the reflection peak, thereby improving coupling efficiency.
[0015] In some embodiments of this application, the etching depth of the second sampling grating is 10nm~20nm. Therefore, while ensuring low loss, the reflectivity and bandwidth of the grating can be precisely controlled to meet the requirements of the device.
[0016] In some embodiments of this application, the waveguide structure surface is provided with a silicon nitride waveguide, a common phase region, a multimode interferometer, and the Y-branch sampling grating structure optically connected in sequence. This allows for the construction of a high-performance, tunable laser resonator.
[0017] In some embodiments of this application, the coupling module includes a polymer waveguide formed by photonic wire bonding (PWB). This enables low-loss coupling between the SOA gain chip region and the external cavity waveguide region, reducing both coupling and transmission losses of the external cavity laser, lowering the required threshold current, and contributing to low power consumption. Furthermore, this coupling method allows for a reduction in the size of the external cavity laser while lowering alignment accuracy.
[0018] In some embodiments of this application, the external cavity waveguide region further includes an indium tin oxide (ITO) layer and an electrode. The ITO layer is disposed on the side of the chalcogenide phase change material layer away from the Y-branch sampling grating structure, and the electrode is disposed on the side of the ITO layer away from the chalcogenide phase change material layer. Thus, an external electrical signal can be converted into thermal energy required to precisely control the state of the chalcogenide phase change material layer, inducing a reversible phase transition between an amorphous and crystalline state in the chalcogenide phase change material, thereby generating significant refractive index modulation and achieving wavelength tuning functionality.
[0019] In some embodiments of this application, the thickness of the indium tin oxide layer is 15 nm to 25 nm. Within this thickness range, the indium tin oxide layer has a small heat capacity, maintains extremely high transparency in the 1550 nm communication band, has low optical loss, and can achieve a fast thermal tuning speed.
[0020] In a second aspect, this application proposes an apparatus comprising the modulation grating Y-branch broadband tuned external cavity laser described in the first aspect. This improves the lifespan and durability of the apparatus and reduces energy consumption.
[0021] In some embodiments of this application, the device includes at least one of an optical fiber sensor, a spectral analysis device, and an optical communication device. Therefore, the modulation grating Y-branch broadband tuned external cavity laser has wide applications and broad prospects. Attached Figure Description
[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein, Figure 1 This is a front view of a modulation grating Y-branch broadband tuned external cavity laser according to an embodiment of this application; Figure 2 This is a top view of a modulation grating Y-branch broadband tuned external cavity laser according to an embodiment of this application; Figure 3 This is a partial enlarged view of a sampling grating according to an embodiment of this application.
[0023] Explanation of reference numerals in the attached figures: 1-Semiconductor optical amplifier (SOA) gain chip region, 2-External cavity waveguide region, 3-Coupled module, 4-Waveguide structure, 5-First sampling grating, 6-Second sampling grating, 7-Chalcogenide phase change material layer, 8-Silicon nitride waveguide, 9-Common phase region, 10-Multimode interferometer, 11-Y branch waveguide, 12-Indium tin oxide layer, 13-Electrode, 14-InP waveguide, 15-InP substrate, 16-N-doped region, 17-Active region, 18-P-doped region, 19-Reflective coating, 20-SiO2 substrate. Detailed Implementation
[0024] The embodiments of this application are described in detail below, with examples of these embodiments shown in the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.
[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit this application; unless otherwise stated, the values of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application).
[0026] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are open-ended expressions, meaning they include what is specified in this application but do not exclude other aspects.
[0027] In the description of this application, all figures disclosed herein, whether or not the words "approximately" or "about" are used, are approximate values. Each figure may vary by less than 10% or by a difference that is considered reasonable by one of the art, such as 1%, 2%, 3%, 4%, or 5%.
[0028] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" means that all real numbers between "0~5" have been listed in this article; "0~5" is just a shortened representation of these numerical combinations.
[0029] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. "First feature" and "second feature" may include one or more of the indicated feature.
[0030] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.
[0031] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.
[0032] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.
[0033] In a first aspect of this application, a modulation grating Y-branch broadband tuned external cavity laser is proposed, with reference to... Figure 1 and Figure 2 The external cavity laser includes: a semiconductor optical amplifier (SOA) gain chip region 1; an external cavity waveguide region 2; and a coupling module 3. The SOA gain chip region 1 and the external cavity waveguide region 2 are coupled together via the coupling module 3. The external cavity waveguide region includes: a waveguide structure 4; a Y-branch sampling grating structure, which is disposed on the surface of the waveguide structure. The Y-branch sampling grating structure has a first sampling grating 5 and a second sampling grating 6. A chalcogenide phase change material layer 7 is disposed on the surface of the first or second sampling grating. The chalcogenide phase change material layer includes interconnected planar portions and protrusions. The protrusions fill the grooves of the first or second sampling grating (see details). Figure 3 This application incorporates a chalcogenide phase-change material layer on a waveguide structure. Chalcogenide phase-change materials possess nanosecond-level phase-state switching speeds, enabling rapid and precise multi-level wavelength tuning of the laser in an extremely short time, thus making it suitable for applications requiring rapid tuning. Furthermore, the non-volatile nature of chalcogenide phase-change materials allows them to maintain a stable state without requiring a power supply after the state transition, effectively reducing the power consumption of the external cavity laser and significantly improving its environmental adaptability and wavelength control accuracy. This provides an ideal solution for the development of high-performance tunable external cavity lasers.
[0034] The Y-branch sampling grating structure exhibits multi-peak reflection spectral characteristics. By precisely designing the difference in the reflection peak spacing between the two interferometer sampling gratings and utilizing the tunable refractive index characteristics of the chalcogenide phase change material layer, the wavelength of the reflection peak of one of the interferometer sampling gratings is adjusted, thereby changing the alignment wavelength and realizing broadband wavelength tuning.
[0035] In this application, the MG-Y external cavity laser system based on the additive vernier effect achieves precise tuning and control of the output wavelength by adjusting the effective refractive index of the dual interferometer arms. Thanks to its longer resonant cavity structure, it is easier to obtain narrow linewidth laser output. Furthermore, by combining the external optical reflector with a chalcogenide phase change material, the nanosecond-level phase modulation capability, non-volatile storage characteristics, and multi-level state switching advantages of the chalcogenide phase change material can be fully utilized. This allows the external cavity laser to achieve rapid wavelength tuning while ensuring no crosstalk between wavelength channels, thus achieving fast, stable, and precise wavelength control.
[0036] The core of the additive vernier effect lies in the interaction of two sampling gratings with slightly different sampling periods, which enables ultra-high sensitivity response or wide-range tuning to minute changes.
[0037] In this application, the working principle of the modulated grating Y-branch broadband tuned external cavity laser is as follows: current is injected into the gain chip region of the semiconductor optical amplifier (SOA), and particle inversion is achieved in its internal active region, which promotes the recombination of charge carriers and holes, thereby generating optical gain and radiating seed light. The seed light is coupled into the external cavity waveguide region and is evenly distributed to the sampling gratings on both sides by a multimode interferometer. The light reflected back from the two sampling gratings is interfered and combined by the multimode interferometer and then returns to the gain chip region of the semiconductor optical amplifier (SOA) and exits from the left end of the gain chip region of the semiconductor optical amplifier (SOA).
[0038] Specifically, the gain light generated by the gain chip region of the semiconductor optical amplifier (SOA) is equally distributed via a multimode interferometer and injected into the symmetrical dual channels of the Y-type branch waveguide. The dual channel terminals are integrated with sampling gratings (SG1 / SG2) with small differences in free spectral range (FSR), forming a vernier effect reflection spectrum. The reflected light returns to the multimode interferometer via the original path, and the light field that meets the phase matching condition undergoes coherent enhancement within the multimode interferometer (MMI). A chalcogenide phase change material layer is integrated on top of the SG1 grating region. By applying a control voltage to induce the Joule heating effect, the generated heat is conducted to the chalcogenide phase change material layer through the indium tin oxide (ITO) layer, inducing a reversible phase transition between the amorphous and crystalline states of the chalcogenide phase change material. The phase transition process generates significant refractive index modulation (Δn>0.5), which is equivalent to the dynamic shift of the SG1 reflection wavelength. In the initial state, the light in the SG1 / SG2 reflection spectrum is enhanced due to phase matching. When the wavelength of SG1 shifts, the interference phase condition in the multimode interferometer changes, and the system automatically selects a new resonant wavelength that satisfies coherence enhancement. This achieves efficient wavelength tuning function. Moreover, the phase switching mechanism of the chalcogenide phase change material based on the Joule heating effect has non-volatile characteristics. After the state transition is completed, it can maintain a stable state without maintaining power supply, which can further reduce the power consumption of the device.
[0039] In addition, the modulation grating Y-branch broadband tuned external cavity laser according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the Y-branch sampling grating structure includes a first interferometer arm and a second interferometer arm. The first interferometer arm has the first sampling grating on its surface, and the second interferometer arm has the second sampling grating on its surface. Thus, by independently adjusting the current in the two interferometer arms, thereby changing their refractive index and reflection spectrum, different peak pairs can be aligned with each other. Using minute changes in refractive index, a wavelength tuning range of tens of nanometers or even wider can be achieved.
[0040] In some embodiments of this application, the sulfide phase change material layer comprises antimony sulfide or antimony selenium. Sulfide phase change materials possess nanosecond-level phase change kinetics and are non-volatile, enabling stable and rapid wavelength tuning of external cavity lasers.
[0041] Antimony sulfide (Sb₂S₃) as a functional material possesses advantages such as ultrafast phase transition kinetics, significant refractive index modulation capability at 1550 nm (Δn≈0.5), high thermal stability, and near-zero absorption (k<0.001) near the 1550 nm wavelength, enabling rapid and precise multi-stage wavelength tuning of external cavity lasers. Furthermore, the non-volatile nature of Sb₂S₃ allows it to maintain stable performance even in extreme environments, significantly improving the environmental adaptability and wavelength control accuracy of external cavity lasers.
[0042] Sb₂Se₃ has advantages such as fast switching speed between amorphous and crystalline states, high refractive index difference (Δn≈0.7), near-zero absorption (k<0.001) near 1550nm, and high stability (>2000 cycles), which enable rapid and precise multi-stage wavelength tuning of external cavity lasers.
[0043] It should be noted that current laser wavelength tuning schemes typically require the integration of thermoelectric electrodes and the application of a continuous bias voltage to achieve wavelength shift, which inevitably leads to increased device power consumption. In contrast, the phase switching mechanism of chalcogenide phase change materials based on the Joule heating effect is non-volatile, maintaining a stable state without the need for power supply after the state transition is complete. This characteristic provides a new technical path for developing fast-response, low-power tunable lasers.
[0044] In some embodiments of this application, the thickness of the planar portion in the chalcogenide phase change material layer is 5 nm to 10 nm, for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm. This results in a more uniform distribution of the electric and thermal fields, which helps to achieve a consistent and uniform phase transition, reducing the occurrence of mixed states of partial crystallization and partial amorphization, thereby ensuring the stability and consistency of the external cavity laser's performance.
[0045] In some embodiments of this application, the sampling period of the first sampling grating is 466nm~469nm, for example, it can be 466nm, 467nm, 468nm or 469nm. Therefore, the spacing of the reflection peaks can be adjusted to control the free spectral range, thereby setting the tuning range of the external cavity laser.
[0046] In some embodiments of this application, the duty cycle of the first sampling grating is 30% to 50%, for example, it can be 30%, 35%, 40%, 45%, or 50%. This allows for precise control of the intensity distribution and uniformity of the reflection peak, improving coupling efficiency.
[0047] In some embodiments of this application, the etching depth of the first sampling grating is 10nm~20nm, for example, it can be 10nm, 12nm, 14nm, 16nm, 18nm or 20nm. Therefore, while ensuring low loss, the modulation intensity of the sampling grating can be precisely controlled, thereby determining the reflectivity and bandwidth of each reflection peak.
[0048] In some embodiments of this application, the sampling period of the second sampling grating is 476nm~478nm, for example, it can be 476nm, 476.3nm, 476.5nm, 476.8nm, 477nm, 477.3nm, 477.5nm, 477.8nm, or 478nm. Therefore, the spacing of the reflection peaks can be adjusted to control the free spectral range, thereby setting the tuning range of the external cavity laser.
[0049] In some embodiments of this application, the duty cycle of the second sampling grating is 30% to 50%, for example, it can be 30%, 35%, 40%, 45%, or 50%. This allows for precise control of the intensity distribution and uniformity of the reflection peak, improving coupling efficiency.
[0050] In some embodiments of this application, the etching depth of the second sampling grating is 10nm~20nm, for example, it can be 10nm, 12nm, 14nm, 16nm, 18nm or 20nm. Therefore, while ensuring low loss, the reflectivity and bandwidth of the grating can be precisely controlled to meet the requirements of the device.
[0051] The sampling period, also known as the grating period, refers to the length of a complete sampling unit, which is the sum of the widths of one grating tooth and one slot. The principle of adjusting the sampling period is based on the aforementioned additive vernier effect. The duty cycle refers to the ratio of the width of the grating tooth to the sampling period. The etching depth refers to the depth etched into the waveguide.
[0052] In some embodiments of this application, the waveguide structure surface is provided with a silicon nitride waveguide 8, a common phase region 9, a multimode interferometer 10, and a Y-branch sampling grating structure optically connected in sequence. Due to the wide bandgap characteristics of Si3N4 material, this waveguide structure exhibits excellent high-voltage withstand performance; simultaneously, its inherent low-loss characteristics effectively reduce the overall optical loss of the external cavity laser, thereby significantly reducing the laser's threshold operating voltage. The common phase region aligns the cavity modes and reflection peaks, uniformly and precisely adjusting the optical phase of the light wave passing through this region, ensuring stable and continuous laser output. The multimode interferometer (MMI) is used for beam splitting, combining, and interfering of light, efficiently and uniformly distributing the input optical signal to the sampling gratings on both sides, ensuring that the optical power allocated to the subsequent two interferometer arms is completely consistent, which is a prerequisite for the effective operation of the additive vernier effect. Thus, a high-performance, tunable laser resonator can be constructed.
[0053] In some embodiments of this application, the coupling module includes a polymer waveguide, which is formed by photonic wire bonding (PWB). It is understood that this application utilizes a polymer waveguide to couple an InP waveguide to a silicon nitride waveguide, thereby integrating the SOA gain chip region and the external cavity waveguide region. This achieves low-loss coupling between the SOA gain chip region and the external cavity waveguide region, reducing both the coupling loss and transmission loss of the external cavity laser, lowering the required threshold current, and contributing to low power consumption. Furthermore, this coupling method allows for a reduction in the size of the external cavity laser while lowering alignment accuracy.
[0054] In some embodiments of this application, reference is made to Figure 1 and Figure 2 The external cavity waveguide region also includes an indium tin oxide (ITO) layer 12 and an electrode 13. The ITO layer is disposed on the side of the chalcogenide phase change material layer away from the Y-branch sampling grating structure, and the electrode is disposed on the side of the ITO layer away from the chalcogenide phase change material layer. The ITO layer facilitates the formation of a current-carrying circuit and conducts electro-induced Joule heating to the chalcogenide phase change material layer. Thus, external electrical signals can be converted into the thermal energy required to precisely control the state of the chalcogenide phase change material layer, inducing a reversible phase transition between the amorphous and crystalline states, thereby generating significant refractive index modulation and achieving wavelength tuning functionality.
[0055] In some embodiments of this application, the thickness of the indium tin oxide layer is 15nm to 25nm, for example, it can be 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, or 25nm. Within the above thickness range, the indium tin oxide layer has a small heat capacity, maintains extremely high transparency in the 1550nm communication band, has low optical loss, and can achieve a fast thermal tuning speed.
[0056] It should be noted that other structures of the modulation grating Y-branch broadband tuned external cavity laser of this application can be found in [reference needed]. Figure 1 and Figure 2 This will not be elaborated further in this application specification.
[0057] In a second aspect, this application proposes an apparatus comprising the modulation grating Y-branch broadband tuned external cavity laser of the first aspect of this application. This improves the lifespan and durability of the apparatus and reduces energy consumption.
[0058] In some embodiments of this application, the device includes at least one of an optical fiber sensor, a spectral analysis device, and an optical communication device. Therefore, the modulation grating Y-branch broadband tuned external cavity laser has wide applications and broad prospects.
[0059] Specifically, this grating-Y branch broadband tuned external cavity laser (MG-Y ECL) can be applied in the following fields: 1. Fiber optic sensing field MG-Y ECLs possess a wide wavelength tuning range, meeting the needs of different types of fiber optic sensors for different wavelengths of laser light. This provides fiber optic sensing systems with a rich selection of wavelengths, enabling more precise matching of the sensor's operating wavelength and improving sensing accuracy. Furthermore, by combining MG-Y ECLs with chalcogenide phase change materials, phase switching can be achieved in nanoseconds by applying current to the PCM, thereby changing the refractive index of the grating and achieving wavelength tuning of the laser.
[0060] 2. Spectral analysis High-resolution spectral analysis demands extremely high signal accuracy and reliability, but background noise and environmental interference often lead to signal distortion. The MG-Y ECL, with its unique cavity design, effectively suppresses noise and improves the signal-to-noise ratio, thereby enhancing the quality of spectral data. Furthermore, the introduction of chalcogenide phase change materials can further meet the measurement needs of high-resolution spectroscopy across multiple wavelength ranges.
[0061] 3. Optical communication With the rapid development of applications such as cloud computing, the Internet of Things, and video streaming, global data transmission demand has increased dramatically, placing higher demands on the bandwidth of fiber optic communication systems. MG-Y ECL, by integrating optical components such as gratings, enables efficient wavelength division multiplexing, significantly improving bandwidth utilization. Furthermore, the dynamic wavelength tuning capability of chalcogenide phase change materials can optimize spectrum allocation, effectively alleviating the pressure on limited spectrum resources.
[0062] In summary, the wavelength-tunable MG-Y ECL, incorporating chalcogenide phase change materials, has broad application prospects in various technological fields such as fiber optic sensing, spectral analysis, and optical communication. With continuous technological development and innovation, these application areas will continue to expand and deepen.
[0063] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.
[0064] The following specific embodiments illustrate the solution of this application. It should be noted that these embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0065] Example 1 This modulated grating Y-branch broadband tuned external cavity laser is an improvement on common lasers. The external cavity laser includes a semiconductor optical amplifier (SOA) gain chip region and an external cavity waveguide region, which are coupled together via a coupling module. The external cavity waveguide region includes a waveguide structure and a Y-branch sampling grating structure. The Y-branch sampling grating structure is disposed on the surface of the waveguide structure and includes a first interference arm and a second interference arm. The surface of the first interference arm is provided with a first sampling grating (SG1, sampling period 468nm, duty cycle 40%, etching depth 15nm), and the surface of the second interference arm is provided with a second sampling grating (SG2, sampling period 477nm, duty cycle 40%, etching depth 15nm). The surface of the first sampling grating is provided with an antimony sulfide phase change material layer, which includes interconnected planar portions (planar portions with a thickness of 8nm) and protrusions. The protrusions fill the grooves of the first sampling grating. A detailed structural diagram can be found in [reference needed]. Figure 1 , Figure 2 and Figure 3 .
[0066] Example 2 The structure is the same as in Example 1, except that the sulfur-based phase change material is a selenium-antimony material.
[0067] Comparative Example 1 The structure is the same as in Example 1, except that no sulfur-based phase change material layer is provided.
[0068] During operation, the SOA (Series Optical Amplifier) gain chip provides the necessary optical gain, amplifying the optical signal. The common phase region adjusts the phase resonance condition within the laser cavity by changing the current, achieving fine-tuning of the wavelength. A multimode interferometer couples optical signals along different paths, ensuring efficient transmission. Furthermore, coarse wavelength tuning is achieved using the additive vernier effect. Specifically, by changing the reflector current in one arm of the two-arm Bragg reflector, a phase transition occurs in the chalcogenide phase change material deposited on that arm, altering the overall effective refractive index of the reflector and fine-tuning the Bragg wavelength of that arm, thus controlling the reflection spectrum. Thanks to the non-volatility of the chalcogenide phase change material, the laser's operational stability is further improved. When the peak frequencies of the comb-shaped reflection spectra generated by the two reflectors coincide, the laser threshold condition is met, and the laser outputs light at that frequency. Finally, the semiconductor optical amplifier further amplifies the optical signal before laser output, increasing the output power.
[0069] This application compares the MG-Y external cavity laser incorporating chalcogenide phase change materials with conventional external cavity lasers currently on the market. Using chalcogenide phase change materials allows for more stable grating reflection wavelength shifts, and thanks to the non-volatility of these materials—meaning they can maintain a constant state without continuous voltage application—device power consumption is reduced. Furthermore, the use of photonic wire bonding (PWB) technology not only lowers the requirements for coupling accuracy but also achieves lower coupling losses.
[0070] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.
Claims
1. A modulation grating Y-branch broadband tuned external cavity laser, characterized in that, include: Semiconductor optical amplifier (SOA) gain chip area; External cavity waveguide region; The coupling module connects the SOA gain chip region and the external cavity waveguide region. The external cavity waveguide region includes: Waveguide structure; The Y-branch sampling grating structure is disposed on the surface of the waveguide structure. The Y-branch sampling grating structure is provided with a first sampling grating and a second sampling grating. A sulfur-based phase change material layer is disposed on the surface of the first sampling grating or the second sampling grating. The sulfur-based phase change material layer includes interconnected planar portions and protrusions. The protrusions are filled in the grooves of the first sampling grating or the second sampling grating.
2. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1, characterized in that, The Y-branch sampling grating structure includes a first interferometer arm and a second interferometer arm. The first interferometer arm has the first sampling grating on its surface, and the second interferometer arm has the second sampling grating on its surface.
3. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1 or 2, characterized in that, The thickness of the planar portion of the sulfur-based phase change material layer is 5 nm to 10 nm.
4. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1 or 2, characterized in that, The sampling period of the first sampling grating is 466nm~469nm; and / or, The duty cycle of the first sampling grating is 30%~50%; and / or, The etching depth of the first sampling grating is 10nm~20nm.
5. The modulation grating Y-branch broadband tuned external cavity laser according to claim 4, characterized in that, The sampling period of the second sampling grating is 476nm~478nm; and / or, The duty cycle of the second sampling grating is 30%~50%; and / or, The etching depth of the second sampling grating is 10nm~20nm.
6. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1 or 2, characterized in that, The waveguide structure surface is provided with a silicon nitride waveguide, a common phase region, a multimode interferometer, and the Y-branch sampling grating structure that are optically connected in sequence.
7. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1 or 2, characterized in that, The coupling module includes a polymer waveguide, which is formed by photonic wire bonding (PWB).
8. The modulation grating Y-branch broadband tuned external cavity laser according to claim 1 or 2, characterized in that, The external cavity waveguide region further includes an indium tin oxide layer and an electrode. The indium tin oxide layer is disposed on the side of the sulfide phase change material layer away from the Y-branch sampling grating structure, and the electrode is disposed on the side of the indium tin oxide layer away from the sulfide phase change material layer.
9. A device, characterized in that, Including the modulation grating Y-branch broadband tuned external cavity laser as described in any one of claims 1 to 8.
10. The device according to claim 9, characterized in that, The device includes at least one of fiber optic sensors, spectral analysis equipment, and optical communication equipment.