A laser and a laser apparatus

Abstract

The application provides a laser and a laser device, the laser has a temperature warning zone, and the laser has a kink phenomenon in the temperature warning zone; wherein the maximum temperature of the temperature warning zone is less than the failure temperature of the laser; the kink phenomenon can be designed to stably occur in the temperature warning zone, and the maximum temperature of the temperature warning zone is less than the failure temperature of the laser, so that an effective and identifiable warning mechanism is realized, the chip failure caused by the abnormally high temperature of the module is avoided, and the working reliability of the laser is improved.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more specifically to a laser and laser device with high reliability and safety. Background Technology

[0002] A laser is a device that can convert electrical energy into light energy and output coherent light. It is widely used in many technical fields such as optical communication, industrial processing, biomedicine and precision measurement.

[0003] In existing technologies, temperature control of lasers mostly relies on external thermistor components, such as thermistors (NTCs), thermocouples, and temperature control ICs. These components typically suffer from drawbacks such as slow response, location away from the heat source, high thermal inertia, and high integration difficulty, making it difficult to reflect the actual temperature changes of the laser's active region in real time and accurately.

[0004] In lasers, light is generated through stimulated emission caused by the recombination of electrons and holes in the active region. Whether a laser reaches the conditions for emission depends on the relationship between its gain and loss spectra. When the gain spectrum and loss spectrum are tangent at a certain wavelength, the laser reaches the threshold condition and begins to emit light. The tangent wavelength at this point is the operating wavelength of the laser. As temperature increases, the overall gain spectrum undergoes a redshift, and the tangent wavelength shifts towards longer wavelengths. At certain temperature points, the shape or position of the gain spectrum changes drastically, causing a sudden transition in the laser mode, manifested as the kink phenomenon in the optical power-current (LI) characteristic curve. The occurrence of kinks is usually accompanied by a decrease in laser efficiency, or even device failure.

[0005] However, in the design or manufacture of lasers, current technological trends mainly focus on eliminating the kink phenomenon in lasers to improve laser performance, without realizing the positive use of the kink phenomenon, which is considered a hidden danger in the field, as a warning signal of laser failure. Summary of the Invention

[0006] The purpose of this invention is to pioneer the positive utilization of the Kink phenomenon in laser design and manufacturing, and to provide for the first time a laser structure with its own failure warning function. This structure can be designed to stably limit the Kink phenomenon to a temperature warning zone, and the maximum temperature of this warning zone is less than the failure temperature of the laser, so as to achieve an effective and identifiable warning mechanism and improve the reliability and safety of the laser.

[0007] According to one aspect of the present invention, a laser is provided, wherein the laser has a temperature warning zone in which the laser exhibits a kink phenomenon; wherein the maximum temperature of the temperature warning zone is less than the failure temperature of the laser.

[0008] According to one aspect of the present invention, the laser has an adjacent working area, wherein the minimum temperature of the temperature warning area is greater than or equal to the maximum temperature of the adjacent working area.

[0009] According to one aspect of the present invention, the laser exhibits a kink phenomenon in the temperature warning zone, comprising: in the adjacent working area, any two adjacent working temperature points of the laser correspond to the same laser mode; in the temperature warning zone, at least one working temperature point of the laser corresponds to a different laser mode from its previous working temperature point; wherein, the difference between any two adjacent working temperature points of the previous working temperature point is the same in the adjacent working area or the temperature warning zone.

[0010] According to one aspect of the present invention, the laser exhibits a kink phenomenon in the temperature warning zone, comprising: in the adjacent working zone, the difference in performance parameters corresponding to any two adjacent working temperature points of the laser is m; in the temperature warning zone, the laser has at least one working temperature point whose performance parameter difference with its previous working temperature point is n*m, n≠1; wherein, the previous working temperature point is in the adjacent working zone or the temperature warning zone, the difference in performance parameters between any two adjacent working temperature points is the same, and the performance parameters include at least one of wavelength and output power.

[0011] According to one aspect of the present invention, the laser has a gain curve and a loss curve, the loss curve being a curve of the laser's loss intensity with respect to wavelength, and the gain curve being a curve of the laser's gain coefficient with respect to wavelength; in the adjacent working region, the first first derivative of the loss intensity with respect to wavelength is greater than 0; in the temperature warning region, the second first derivative of the loss intensity with respect to wavelength is less than 0.

[0012] According to one aspect of the present invention, the loss curve has a loss peak (λ1, α1), which is the point on the loss curve with the greatest loss intensity, and the loss peak (λ1, α1) has a loss peak wavelength λ1 and a loss peak intensity α1; the adjacent working area is adjacent to the temperature warning area through the loss peak (λ1, α1).

[0013] According to one aspect of the present invention, the loss curve has adjacent boundary points (λ2, α2), which are boundary points on the side of the adjacent working area away from the temperature warning area. The adjacent boundary points (λ2, α2) have adjacent boundary point wavelength λ2 and adjacent boundary point intensity α2. The laser has a first operating wavelength Δλ1, which is the difference between the loss peak wavelength λ1 and the adjacent boundary point wavelength λ2, where 20nm ≤ |Δλ1| ≤ 40nm.

[0014] According to one aspect of the present invention, the first derivative of the first loss is greater than or equal to 0.5 cm. -1 / nm; the ratio of the intensity α1 of the loss peak to the intensity α2 of the adjacent boundary point is greater than or equal to 1.5.

[0015] According to one aspect of the present invention, the laser further has a first loss region adjacent to the adjacent working region on a side away from the temperature warning region; the loss curve in the first loss region includes a half-maximum stop (λ3, α3), the half-maximum stop (λ3, α3) having a half-maximum stop wavelength λ3 and a half-maximum stop loss intensity α3; the first derivative of the half-maximum stop loss intensity α3 with respect to wavelength is equal to 0; the laser further has a half-maximum bandwidth Δλ2, the half-maximum bandwidth Δλ2 being the difference between the loss peak wavelength λ1 and the half-maximum stop wavelength λ3, where |Δλ1| / |Δλ2|≤0.7.

[0016] According to one aspect of the present invention, the gain curve includes a gain peak (λ). 增峰 α 增峰 ) and gain stop (λ) 增止 ,0); the gain peak point (λ) 增峰 α 增峰 It has a gain peak wavelength λ 增峰 and gain peak intensity α 增峰 The gain stop (λ) 增止 ,0) has a gain stop wavelength λ 增止 The gain peak intensity is 0; the gain curve has a gain width Δλ3, which is the gain peak wavelength λ. 增峰 With the gain stop wavelength λ 增止 The difference is 10nm≤|△λ3|<40nm.

[0017] According to one aspect of the present invention, the laser further has a laser cavity length L, where L ≥ 3 mm.

[0018] According to one aspect of the present invention, the AR film layer of the laser has an adjacent working reflectivity of R in the adjacent working area, where 0 < R ≤ 0.1.

[0019] According to one aspect of the present invention, the material of the AR film includes at least one selected from Al2O3, SiO2, SiN, Ta2O5, ZnS, ZnSe, HfO2 and TiO2.

[0020] According to one aspect of the present invention, the difference between the maximum temperature of the temperature warning zone and the failure temperature of the laser is ΔT, where 5℃≤ΔT≤10℃.

[0021] According to one aspect of the present invention, this application also proposes a laser device comprising the laser described above.

[0022] This invention proposes a laser with a temperature warning zone in which the laser exhibits a kinking phenomenon; wherein the maximum temperature in the temperature warning zone is less than the laser's failure temperature. Compared with existing technologies, the laser proposed in this invention has the following beneficial effects: First, this invention introduces a temperature warning zone design. By defining the performance behavior characteristics of the laser within a certain temperature range, an internal temperature monitoring mechanism is formed. This temperature warning zone corresponds to a specific temperature range within the laser's operating temperature, used to identify whether the laser is in a near-failure state. This solution can identify and judge the thermal risks of the laser without relying on external temperature control devices, significantly improving system integration and thermal response efficiency.

[0023] Secondly, during the design or manufacturing process, lasers may experience the kink phenomenon within the temperature warning zone. The kink phenomenon, characterized by abrupt changes in optical performance parameters such as output power, mode, or wavelength, is highly sudden, sensitive, and observable. Intentionally "fixing" it within the temperature warning zone can transform the internal physical behavior of the laser into a clear criterion event, providing a stable, repeatable, and easily detectable warning signal, thus facilitating autonomous perception of the device's health status.

[0024] Finally, this invention further limits the maximum temperature of the temperature warning zone to be less than the laser's failure temperature. This design ensures that the kink phenomenon is reliably identified before the laser fails, allowing the system to perform necessary response operations (such as reducing power, shutting down the laser, and activating the cooling module) before the device completely fails, thereby effectively avoiding failure accidents caused by overheating. Through this setting, this invention achieves a closed-loop thermal management logic of "early identification - timely response," improving the overall safety, stability, and lifespan of the laser.

[0025] In summary, during the design or manufacturing process, the laser provided by this invention effectively overcomes the problems of temperature warning relying on external components, response lag, and unclear identification in the prior art by embedding a temperature warning zone, structurally guiding the location of the Kink phenomenon, and setting a clear upper temperature limit boundary. It has significant advantages such as simple structure, clear identification mechanism, fast response, and low cost, and is suitable for laser application scenarios with high requirements for temperature reliability and system stability. Attached Figure Description

[0026] Figure 1 This is a loss curve and gain curve diagram of a laser used in one embodiment of the present invention in terms of loss-gain intensity-wavelength coordinates; Figure 2 This is a loss curve and gain curve diagram of the laser used in another embodiment of the present invention in terms of loss-gain intensity-wavelength coordinates; Figure 3 This is the wavelength-reflectivity curve corresponding to the laser used in one embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the laser kink phenomenon temperature point in the early warning working area, as used in one embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] The purpose of this invention is to provide a laser structure that can be designed to stably limit the kink phenomenon to a temperature warning zone during the design and production of lasers, and the maximum temperature of this temperature warning zone is less than the failure temperature of the laser, so as to achieve an effective and identifiable warning mechanism and improve the operational reliability and safety of the laser.

[0031] To better understand the above technical solutions, the following description will be provided in conjunction with the accompanying drawings and specific embodiments: An embodiment of the present invention provides a laser, such as Figure 4 As shown, the laser has a temperature warning zone 200, in which the laser exhibits a kink phenomenon; wherein the maximum temperature of the temperature warning zone is less than the failure temperature of the laser. In one embodiment of the present invention, specifically, as follows... Figure 4 As shown, a laser is provided with a temperature warning zone 200 ranging from 75°C to 145°C. The laser's failure temperature is 145°C, and the point at which the Kink phenomenon occurs is 80°C. In other words, the laser exhibits the Kink phenomenon within this temperature warning zone 200. One embodiment of the invention is as follows... Figure 4 As shown, the Kink phenomenon occurs at 80℃, during which a power jump occurs. Before the Kink phenomenon occurs at 80℃, the power change is linear. The Kink phenomenon occurs at 80℃, which is the inflection point of the power jump. The power drop at this point is n times the previous linear power drop, where n≠1.

[0032] Specifically, the temperature warning zone refers to the temperature range within which a laser begins to exhibit abnormal performance trends as its temperature gradually increases. This range typically lies between the laser's normal operating temperature and its failure temperature, and its temperature range can be set according to the device structure, electrical performance, packaging method, and specific application conditions. As a transitional area for monitoring whether a laser is approaching performance degradation or impending failure, the temperature warning zone has predictive value.

[0033] Specifically, the kink phenomenon refers to the physical phenomenon where, under certain operating conditions (especially temperature), the output characteristic curves (such as power, laser mode, or wavelength) of a laser exhibit a significant nonlinear inflection point or abrupt change. It commonly appears as a "breakpoint" or "bend" in the LI curve (optical power-current), and can also manifest as mode jumps, abnormal wavelength fluctuations, etc. This abrupt change reflects a drastic change in the laser's internal gain and loss mechanisms or mode competition mechanisms, and is often an important signal that device performance is beginning to degrade.

[0034] Specifically, the maximum temperature in the temperature warning zone refers to the upper limit of the temperature in the aforementioned temperature warning zone, that is, the boundary value closest to the failure temperature in this zone; the failure temperature of a laser refers to the critical temperature at which the structure, output performance, or reliability of the laser is irreversibly damaged due to overheating, and is usually determined through reliability testing.

[0035] The laser described in this embodiment includes a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an upper confinement layer, a cover layer, a dielectric layer, and a first electrode located on one side of the substrate, and a second electrode located on the other side of the substrate; on one side of the substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer are sequentially arranged, a ridge region is formed on the upper confinement layer, the cover layer is disposed on the ridge region, on the upper confinement layer, the dielectric layer covers the region between the edge of the cover layer and the edge of the upper confinement layer, and the first electrode is disposed on the cover layer and contacts the dielectric layer. In this embodiment, by designing the cavity length L of the laser, the cavity length L of the laser is made such that L≥3mm, and the adjacent working reflectivity of the AR film layer of the laser in the adjacent working region is R, where 0<R≤0.1. Among them, the AR film layer includes one or several combinations of Al2O3, SiO2, SiN, Ta2O5, ZnS, ZnSe, HfO2, and TiO2 as the semiconductor materials for generating the AR film layer. That is, the adjacent working reflectivity of the AR film layer in the adjacent working region is R, where 0<R≤0.1. Through the above design, the laser exhibits a kink phenomenon in the temperature warning region, and it is possible to capture the pre-signal of performance degradation. As an obvious non-linear change point, kink has good identifiability and repeatability and is suitable as a warning criterion. The technical effects of this design include, but are not limited to: First, the kink phenomenon, as a direct manifestation of the sudden change of internal optical parameters, can provide an immediate warning signal based on real physical data; second, it avoids the problem of response hysteresis of traditional external temperature-sensitive components; third, it can be linked with the control system to trigger protection measures such as power limit and automatic cooling to prevent the further expansion of the failure and malfunction range.

[0036] In this embodiment, the maximum temperature in the temperature warning region is less than the failure temperature of the laser. In actual application scenarios, if the temperature in the temperature warning region exceeds the failure temperature, even if the kink is detected, the laser is already in an irreversible damaged state, and the warning will lose its practical effect. Therefore, it is necessary to limit the upper temperature limit of the warning region below the failure temperature. And this design provides sufficient reaction time for the control system, enhances safety redundancy; can intervene in advance, reduce the damage risk, and extend the device life.

[0037] A laser provided in an embodiment of the present invention, wherein the laser has an adjacent working region, and the minimum temperature in the temperature warning region is greater than or equal to the maximum temperature in the adjacent working region.

[0038] Specifically, the adjacent working region corresponds to the temperature range in which the laser operates normally; the minimum temperature in the temperature warning region may refer to the starting temperature point at which the output wavelength of the laser is about to enter drift, the mode is about to jump, the power suddenly changes, and other abnormal phenomena.

[0039] Taking the output wavelength as an example, the maximum temperature of the adjacent working region refers to the highest working temperature point at which the output wavelength remains within the designed working wavelength band, corresponding to the upper temperature limit of the stable wavelength output range. Specifically, the minimum temperature of the temperature warning region is greater than or equal to the maximum temperature of the adjacent working region. The above design ensures that when the laser output wavelength transitions from the normal state (adjacent working region) to the temperature warning region, there is a clear temperature boundary. By strictly defining the temperature corresponding range of the wavelength output interval, it is possible to clearly identify when the laser is about to deviate from the normal working state. And it can enhance the basis for setting the threshold of the wavelength control system: binding the wavelength change state to the temperature boundary, enabling the control system to have a clear physical judgment criterion.

[0040] A laser provided by an embodiment of the present invention has a kink phenomenon in the warning temperature region, including: in the adjacent working region, the laser modes corresponding to any two adjacent working temperature points of the laser are the same. Specifically, the working temperature point refers to multiple discrete temperature measurement points divided within the working temperature range of the laser at a fixed step size (such as 1 °C or 10 °C). Each temperature point corresponds to a set of output performance parameters (such as wavelength, power, laser mode, etc.) for monitoring or identifying the operating state of the laser. The laser mode refers to the combined state of the longitudinal mode and the transverse mode exhibited by the laser under specific working conditions, which is a key parameter characterizing the laser output characteristics. Among them: the longitudinal mode refers to the standing wave mode formed by light along the propagation direction (usually the cavity axis direction) in the laser resonator. It reflects the frequency or wavelength distribution characteristics of the laser output and determines the spectral structure of the laser. The transverse mode refers to the distribution mode of the optical field on the cross-section perpendicular to the propagation direction, describing the form of the energy distribution of the laser beam in space. Different transverse modes correspond to different beam qualities and focusing characteristics. The same laser mode means that at any two adjacent working temperature points, the combined state of the longitudinal mode and the transverse mode output by the laser remains unchanged. That is to say, at these temperature points, the laser output by the laser has the same spectral structure and spatial energy distribution form, indicating that the device operation is in a stable working interval. For example, in the adjacent working region, when the laser is measured at a continuous plurality of temperature points (such as every 1 °C), the laser mode of its output does not change, that is, there are no new mode competitions, mode jumps or mode multiplexing and other phenomena. This state of the same laser mode reflects that the internal gain and loss mechanisms of the laser are stable and have not entered the stage of thermal disturbance or instability.

[0041] In the temperature warning region, there is at least one operating temperature point of the laser whose corresponding laser mode is different from that of its previous operating temperature point; specifically, the at least one operating temperature point is the kink temperature occurrence point of the laser, and the at least one operating temperature point and its previous operating temperature point are two adjacent operating temperature points. In addition, the difference in laser modes means that when the laser operates at different temperature points, the combined state of the output laser in the longitudinal mode and the transverse mode changes, manifested as a significant mutation or jump in the output characteristics of the laser. As mentioned above, the laser mode consists of two parts: the longitudinal mode refers to the standing wave mode formed by light along the propagation direction (usually the cavity axis direction) in the laser resonator. It reflects the frequency or wavelength distribution characteristics of the laser output and determines the spectral structure of the laser. The transverse mode refers to the distribution mode of the light field on the cross-section perpendicular to the propagation direction, describing the energy distribution pattern of the laser beam in space. Different transverse modes correspond to different beam qualities and focusing characteristics. The difference in laser modes is manifested as the occurrence of one or more of the following situations: First, longitudinal mode transition: As the temperature rises, a slight change in the cavity length or refractive index of the laser causes a change in the resonance condition, and the output wavelength jumps from one longitudinal mode to another; Second, multi-mode to single-mode or single-mode to multi-mode: The laser originally operates in a single mode, and after the temperature reaches a certain critical value, multiple operating modes (multi-mode output) appear, or vice versa; Third, transverse mode transition: The laser output spot structure jumps from the fundamental mode to the high-order mode, or phenomena such as mode mixing and edge enhancement occur; Fourth, enhanced mode competition: The competition between the originally dominant laser mode and other modes intensifies, resulting in a decrease in the output power stability or a distortion of the L-I curve; Fifth, sudden change in output characteristics: Among the continuous operating temperature points of the laser, parameters such as the output wavelength, power, or spectral morphology undergo non-linear and sudden jumps, usually corresponding to the laser mode transition.

[0042] Among them, the previous operating temperature point is in the adjacent working region or the temperature warning region, and the difference between any two adjacent operating temperature points is the same. Specifically, the previous operating temperature point is the previous operating temperature point of the kink occurrence point, and this previous temperature operating point can be in the adjacent working region or in the temperature warning region.

[0043] The laser provided in an embodiment of the present invention has a kink phenomenon in the warning temperature region, including: in the adjacent working region, the change rate of the performance parameters between any two adjacent operating temperature points of the laser is y; in the temperature warning region, there is at least one operating temperature point of the laser whose change rate of the performance parameters between it and its previous operating temperature point is x, and x≠y; among them, the previous operating temperature point is in the adjacent working region or the temperature warning region, and the difference between any two adjacent operating temperature points is the same; the performance parameters include at least one of wavelength, output power, and laser mode, and the laser mode is 0 or 1.

[0044] It should be understood that the laser modes proposed in this application including 0 or 1 do not mean that the laser modes of the laser only include two, that is, 0 and 1 do not correspond one-to-one to a certain laser mode. It can be that 0 represents one specific laser mode (it can be understood that the specific laser mode described here is the laser mode that the laser should have when the operating temperature of the laser is within the temperature defined by the adjacent working area), and 1 represents other laser modes except the specific laser mode. Specifically, in the adjacent working area, the laser mode of the laser remains one specific laser mode, and in the warning temperature area, the laser mode of the laser changes and becomes other laser modes different from the specific laser mode.

[0045] In one embodiment, in the adjacent working area, the change rate of the performance parameters between any two adjacent operating temperature points of the laser is y; in the temperature warning area, there is at least one operating temperature point of the laser whose change rate of the performance parameters with respect to its previous operating temperature point is x, where x≠y, including: setting two adjacent operating temperature points of the laser as T1 and T2 respectively, the performance parameter corresponding to T1 is A1, and the performance parameter corresponding to T2 is A2, then the change rate of the performance parameters between T1 and T2 is (A2 - A1) / (T2 - T1).

[0046] A laser provided by an embodiment of the present invention, the laser exhibits a kink phenomenon in the warning temperature area, including: in the adjacent working area, the laser modes corresponding to any two adjacent operating temperature points of the laser are the same (that is, the laser mode is 0 or 1); in the temperature warning area, there is at least one operating temperature point of the laser whose corresponding laser mode is different from that of its previous operating temperature point.

[0047] It should be understood that when the performance parameters are wavelength and output power, x and y can be fixed values or interval ranges.

[0048] A laser provided by an embodiment of the present invention, the laser exhibits a kink phenomenon in the warning temperature area, including: in the adjacent working area, the difference between the performance parameters corresponding to any two adjacent operating temperature points of the laser is m; in the temperature warning area, there is at least one operating temperature point of the laser whose difference in performance parameters from its previous operating temperature point is n*m, where n≠1; wherein, the previous operating temperature point is in the adjacent working area or the temperature warning area, and the difference between any two adjacent operating temperature points is the same, and the performance parameters include at least one of wavelength and output power.

[0049] Specifically, for this embodiment, the laser proposed in this application has at least a low temperature drift characteristic in the adjacent working area. In the adjacent working area, the wavelength change with temperature can include but is not limited to being less than or equal to 0.2 nm / °C. The operating wavelength in the temperature warning area (corresponding to the last temperature point in the adjacent working area) can include but is not limited to 970 nm. When the temperature exceeds this value and reaches the temperature warning area (the first temperature point), the wavelength is 990 nm, and the change in wavelength with temperature is constant at 0.33 nm / °C; the power only has a sudden change at the critical point. In one embodiment of the present invention, when the temperature in the adjacent working area changes by 10 °C, the power drops by 1 W. When the temperature rises by 1 °C from the power corresponding to the last temperature point in the adjacent working area to the first temperature point in the warning working area, the power drops by 3 W. After that, the change in power with temperature in the warning working area after dropping 3 W is basically the same as that in the adjacent working area.

[0050] For the above embodiment, regarding the feature "in the adjacent working area, the difference between the performance parameters corresponding to any two adjacent operating temperature points of the laser is m." In the adjacent working area, the difference between the performance parameters corresponding to any two adjacent operating temperature points of the laser is m. In this embodiment, the performance parameter of the laser is the output wavelength or the output power. First, taking the output wavelength as an example, in the adjacent working area, when the temperature rises by 1 °C, the wavelength changes by approximately 0.1 nm / °C. That is, if the operating temperature points T1 and T2 are two adjacent temperature points with a difference of 1 °C, the output wavelengths are 969.9 nm and 970.0 nm respectively, and the difference is m = 0.1 nm, showing a linear and predictable thermal drift characteristic. Second, when the power is used as the performance parameter, in the adjacent working area, when the temperature of the laser rises by 10 °C, the output power drops by approximately 1 W. Converted to the unit temperature drop, it is: m = 1 W / 10 °C, that is, the power change between any two adjacent temperature points (with a difference of 10 °C) is 1 W.

[0051] For the above embodiments, regarding the feature "in the temperature warning region, the difference between the performance parameter corresponding to at least one operating temperature point of the laser and the performance parameter corresponding to its previous operating temperature point is n*m, where n≠1.", first, taking the output wavelength as an example, when the temperature rises from the last point T2 in the adjacent operating region to the first point T3 in the temperature warning region (T2 and T3 differ by 1°C), the output wavelength of the laser suddenly changes from 970 nm to 990 nm, and the wavelength mutation amplitude is 20 nm. Compared with the linear drift of only 0.1 nm per 1°C in the adjacent operating region, the mutation value here is n*m = 20 nm. Substituting m = 0.1 nm, we get n = 200 ≠1. Second, when taking power as the performance parameter, in the power dimension, the power at the Kink temperature sending point (at least one temperature point) drops by 3W compared with the previous temperature operating point, while in the adjacent operating region, it only drops by 1W per 10°C. Here, it is equivalent to: n*m = 3W. Substituting m = 0.1W, we get n = 3 ≠ 1.

[0052] According to one aspect of the embodiments of the present invention, the laser exhibits a kink phenomenon in the warning temperature region, including: in the adjacent operating region, the difference between the performance parameters corresponding to any two adjacent operating temperature points of the laser is m, where m<0; in the temperature warning region, the difference between the performance parameter corresponding to at least one operating temperature point of the laser and the performance parameter corresponding to its previous operating temperature point is n*m, where n>1; wherein, the previous operating temperature point is in the adjacent operating region or the temperature warning region, and the difference between any two adjacent operating temperature points is the same, and the performance parameter includes the output power.

[0053] Specifically, for this embodiment, as shown in Table 1 for the embodiment of the change in output power as the performance parameter, specifically, in this embodiment, m<0 and n>1.

[0054] Table 1 Table of changes in output power as the performance parameter <![CDATA[Adjacent area point T0]]> - <![CDATA[P0]]> - - <![CDATA[Adjacent area point T1]]> ΔT=10℃ <![CDATA[P1=P0-1W]]> m=-1W, m<0 No (linear region) <![CDATA[Early warning area point T2]]> ΔT=1℃ <![CDATA[P2=P1-3W]]> n*m=3×(-1W)=-3W, n=3, m=-1, n>1 kink occurrence point <![CDATA[Early warning area point T3]]> ΔT=10℃ <![CDATA[P3=P2-1W]]> m=-1W, m<0 No (Restores linearity) According to one aspect of the embodiments of the present invention, the laser exhibits a kink phenomenon in the warning temperature region, including: in the adjacent operating region, the difference between the performance parameters corresponding to any two adjacent operating temperature points of the laser is m, where m>0; in the temperature warning region, the difference between the performance parameter corresponding to at least one operating temperature point of the laser and the performance parameter corresponding to its previous operating temperature point is n*m, where n>1; wherein, the previous operating temperature point is in the adjacent operating region or the temperature warning region, and the difference between any two adjacent operating temperature points is the same, and the performance parameter includes the wavelength.

[0055] Specifically, for this embodiment, as shown in Table 2 for the embodiment of the change in wavelength as the performance parameter, in this embodiment, m>0 and n>1.

[0056] Table 2 Table of wavelength variation as a performance parameter <![CDATA[Adjacent area point T0]]> - 969nm - - <![CDATA[Adjacent area point T1]]> ΔT=10℃ 970.0nm m = +1nm, m>0 no <![CDATA[Warning area point T2]]> ΔT=1℃ 990.0nm (jumping to 20nm) n*m = 20×1 = +20nmn>1 kink points <![CDATA[Early warning area point T3]]> ΔT=10℃ 993.3nm 3.3nm, m>0 no According to one aspect of an embodiment of the present invention, as Figure 1 shown, a laser provided by an embodiment of the present invention has a loss curve, which is a curve of the laser loss intensity with respect to wavelength. The laser also has a temperature warning zone and an adjacent working zone. Among them, in the loss gain intensity - wavelength coordinate system, the adjacent working zone is adjacent to the temperature warning zone.

[0057] Specifically, as Figure 1 shown, according to different working states of the laser, its working range is set to two adjacent regions: the adjacent working zone 100 and the temperature warning zone 200. In the coordinate system where the loss - gain intensity varies with wavelength, the adjacent working zone 100 and the temperature warning zone 200 are adjacent to each other. The adjacent working zone corresponds to the wavelength range in which the laser operates normally; the temperature warning zone represents a dangerous section indicating that the laser temperature is approaching the failure temperature when the laser wavelength enters this region. Through the division of the adjacent working zone 100 and the temperature warning zone 200, the laser system can clearly distinguish the safe operating state and the critical warning state. Since the temperature warning zone 200 is directly adjacent to the adjacent working zone 100 (the adjacent working zone corresponds to the wavelength range in which the laser operates normally) at its working wavelength, once the laser wavelength gradually shifts to the edge of the temperature warning zone due to temperature increase, the laser system can quickly sense and issue a warning signal of over - high temperature.

[0058] Specifically, this adjacent region design provides a buffer transition zone: the laser does not suddenly jump from a safe state to an unstable or damaged state, but first enters the warning zone, and at this stage the system has time to respond. The close connection between the adjacent working zone 100 and the temperature warning zone 200 ensures that even subtle wavelength changes caused by temperature increase can be captured, thus preventing problems from accumulating to an irreversible level. In short, this feature makes temperature monitoring more sensitive and continuous, making the laser operation more controllable and safe.

[0059] In addition, in contrast, traditional technologies generally only have a single temperature upper limit or alarm point, and do not use wavelength division to provide an early warning. Therefore, in existing solutions, the laser often triggers protection or shutdown only when the temperature is already too high and the performance has significantly declined, which belongs to passive protection. The present invention realizes an improvement in active warning by setting a temperature warning zone and refining the signs of temperature over - limit into early change signals in wavelength.

[0060] According to one aspect of an embodiment of the present invention, the laser has a gain curve and a loss curve. The loss curve is a curve of the loss intensity of the laser with respect to wavelength, and the gain curve is a curve of the gain coefficient of the laser with respect to wavelength; in the adjacent operating region, the first derivative of the loss with respect to wavelength of the loss intensity is greater than 0; in the temperature warning region, the second derivative of the loss with respect to wavelength of the loss intensity is less than 0. Specifically, the loss curve has a first derivative of loss, which is the first derivative of the loss intensity with respect respect to wavelength in the adjacent operating region of the loss curve; the loss curve also has a second derivative of loss, which is the first derivative of the loss intensity with the wavelength in the temperature warning region of the loss curve; the laser also has an actual temperature T 实际 and a warning threshold temperature T0; wherein, when the actual temperature T 实际 is less than or equal to the warning threshold temperature T0, the first derivative of the loss is greater than 0, and when the actual temperature T 实际 is greater than the warning threshold temperature T0, the second derivative of the loss is less than 0.

[0061] Specifically, the loss curve α(λ) refers to the quantitative functional relationship of the total optical loss of the laser resonator measured under preset driving conditions with respect to the change of wavelength λ. The ordinate of the loss curve is the loss intensity α (unit: cm⁻¹), and the abscissa is the wavelength λ (unit: nm). The adjacent operating region refers to the continuous wavelength interval in the three-dimensional coordinate system of loss-gain-wavelength that corresponds to the safe operating temperature range (T ≤ T0) of the laser and satisfies a net gain greater than zero. This interval is adjacent to the temperature warning region and is bounded by the loss peak point (λ1, α1). The temperature warning region refers to the wavelength interval that the output spectrum inevitably slips into from the adjacent operating region when the laser temperature is slightly higher than the warning threshold T0. The slope of the loss curve in this interval is negative. The first derivative of the loss dα / dλ|1 is the slope obtained by differentiating the loss curve α(λ) with respect to the wavelength λ in the adjacent operating region, which reflects the direction and sensitivity of the influence of wavelength perturbation on loss at the safe temperature. Among them, dα / dλ|1 > 0. The second derivative of the loss dα / dλ|2 is the slope obtained by differentiating the loss curve α(λ) with respect to the wavelength λ in the temperature warning region, which reflects the trend of loss change when the wavelength continues to redshift in the initial stage of overheating. Among them, dα / dλ|2 < 0.

[0062] In addition, a natural threshold trigger is constructed through the "first derivative sign flip of the loss curve" mechanism where the first derivative of the loss in the adjacent working area is greater than 0 and the first derivative of the loss in the temperature warning area is less than 0. In the adjacent working area, the first derivative of the loss being greater than 0 indicates that although the laser has a temperature rise, it is within a safe range. Once the temperature exceeds the threshold T0 and enters the temperature warning area, the first derivative of the loss curve immediately flips. The instantaneous change in the sign of the first derivative of the loss curve is more sensitive than the absolute temperature drift, and can give an early warning before a significant power degradation occurs.

[0063] In an optional embodiment of the present invention, as Figures 1-3 shown, the loss curve has a loss peak point (λ1, α1), and the loss peak point (λ1, α1) is the point on the loss curve with the maximum loss intensity. The loss peak point has a loss peak wavelength λ1 and a loss peak intensity α1; wherein, the adjacent working area is adjacent to the temperature warning area through the loss peak point (λ1, α1). According to one aspect of the embodiment of the present invention, the loss curve has a loss peak point (λ1, α1), the loss peak point (λ1, α1) is the point on the loss curve with the maximum loss intensity, the loss peak point (λ1, α1) has a loss peak wavelength λ1 and a loss peak intensity α1; the adjacent working area is adjacent to the temperature warning area through the loss peak point (λ1, α1).

[0064] Specifically, by designing the loss peak point (λ1, α1) as the demarcation point between the adjacent working area and the temperature warning area, in this way, on the left side (short wavelength side) of the loss peak point, the slope of the loss curve is positive, and on the right side (long wavelength side), the slope is negative. The signs on both sides are opposite, and the curve shape or curvature is symmetric, meeting the requirement of dα / dλ > 0 in the working area and dα / dλ < 0 in the warning area without additional design, ensuring the robustness and consistency of the warning criterion.

[0065] According to one aspect of the embodiment of the present invention, as Figures 1-3 shown, the loss curve has an adjacent boundary point (λ2, α2), and the adjacent boundary point (λ2, α2) is the boundary point on the side of the adjacent working area away from the temperature warning area. The adjacent boundary point (λ2, α2) has an adjacent boundary point wavelength λ2 and an adjacent boundary point intensity α2; the laser has a first working bandwidth △λ1, and the first working bandwidth △λ1 is the difference between the loss peak wavelength λ'1 and the adjacent boundary point wavelength λ2, 20nm ≤ |△λ1| ≤ 40nm.

[0066] According to one aspect of the embodiment of the present invention, the first derivative of the loss is greater than or equal to 0.5 cm -1 / nm; the ratio of the loss peak intensity α1 to the adjacent boundary point intensity α2 is greater than or equal to 1.5.

[0067] According to one aspect of the embodiment of the present invention, as Figures 1-3As shown, the laser also has a first loss region, which is adjacent to the adjacent working area on the side away from the temperature warning region; the loss curve in the first loss region includes a half-maximum stop (λ3, α3), which has a half-maximum stop wavelength λ3 and a half-maximum stop loss intensity α3; the first derivative of the half-maximum stop loss intensity α3 with respect to wavelength is equal to 0; the laser also has a half-maximum bandwidth Δλ2, which is the difference between the loss peak wavelength λ1 and the half-maximum stop wavelength λ3, wherein |Δλ1| / |Δλ2|≤0.7.

[0068] According to one aspect of the embodiments of the present invention, such as Figures 1-3 As shown, the gain curve includes the gain peak (λ). 增峰 α 增峰 ) and gain stop (λ) 增止 ,0); the gain peak point (λ) 增峰 α 增峰 It has a gain peak wavelength λ 增峰 and gain peak intensity α 增峰 The gain stop (λ) 增止 ,0) has a gain stop wavelength λ 增止 The gain peak intensity is 0; the gain curve has a gain width Δλ3, which is the gain peak wavelength λ. 增峰 With the gain stop wavelength λ 增止 The difference is 10nm≤|△λ3|<40nm.

[0069] According to one aspect of the embodiments of the present invention, such as Figure 1 As shown, the loss curve of the adjacent working area has an adjacent boundary point (λ2, α2). The adjacent boundary point (λ2, α2) is the boundary point of the adjacent working area away from the temperature warning zone. The adjacent boundary point has an adjacent boundary point wavelength λ2 and an adjacent boundary point loss intensity α2; wherein, the adjacent boundary point (λ2, α2) is the shortest wavelength endpoint of the adjacent working area, such as... Figure 1 As shown, if the laser wavelength is lower than the wavelength λ2 of the adjacent boundary point, the laser enters the first loss region 300. A laser located in the first loss region can also emit relevant wavelengths; however, the first loss region 300 is a region where the laser device suffers severe efficiency loss. When the laser is operating normally, it has a first operating wavelength width, which is the difference between the loss peak wavelength λ1 and the wavelength λ2 of the adjacent boundary point; wherein the first operating wavelength width is greater than or equal to 20 nm and less than or equal to 40 nm.

[0070] In an optional embodiment of the present invention, the first derivative of the first loss is greater than or equal to 0.5 cm. -1 / nm; the ratio of the loss peak intensity α1 to the adjacent boundary point loss intensity α2 is greater than or equal to 1.5.

[0071] Specifically, firstly, when dα / dλ ≥ 0.5 cm⁻¹ / nm, the loss changes by at least 0.5 cm⁻¹ for every 1 nm wavelength drift, far exceeding typical spectral noise levels (≈0.1–0.2 cm⁻¹), effectively preventing minute fluctuations from being drowned out by noise. Furthermore, increasing the slope simultaneously suppresses system drift, ensuring that factors other than temperature (such as fine-tuning of the drive current) have minimal impact on the warning criteria. A larger slope also means that once the temperature approaches the threshold, a slight redshift in the wavelength can quickly cause dα / dλ to flip from positive to negative, significantly reducing the amount of wavelength drift and time required for triggering the judgment. Secondly, α1 / α2 ≥ 1.5 ensures a significant height difference between the peak and the boundary point, allowing the detection algorithm or hardware circuit to easily locate the peak, reducing false positives and false negatives. Furthermore, the peak significance of α1 / α2 ≥ 1.5 exceeds that of common sidelobe or other mode fluctuations (typically ≈1.2–1.3), thus avoiding the creation of false Kink signals caused by tolerance or multimode interference.

[0072] An optional embodiment of the present invention, such as Figure 1 As shown, the laser also has a first loss region, wherein, in the loss-gain intensity-wavelength coordinate system, the first loss region is adjacent to the adjacent working region on the side away from the temperature warning region; the loss curve of the first loss region has a half-maximum stop (λ3, α3), the half-maximum stop of the loss curve has a half-maximum stop first derivative, the half-maximum stop first derivative is equal to 0, the half-maximum stop has a half-maximum stop wavelength λ3 and a half-maximum stop loss intensity α3; the laser also has a half-maximum bandwidth, the half-maximum bandwidth being the difference between the loss peak wavelength λ1 and the half-maximum stop wavelength λ3; the ratio of the first working bandwidth to the half-maximum bandwidth is less than or equal to 0.7.

[0073] Specifically, the ratio of the first operating wavelength width Δλ1 = λ1 – λ2 to the half-height wavelength width Δλ3 = λ1 – λ3 is set to be less than or equal to 0.7. Firstly, this ensures that the adjacent operating region is located in a flat section far from the half-height stop. The first derivative at the half-height stop is zero, meaning that the loss curve is least sensitive to wavelength changes near λ3. Controlling Δλ1 within 70% of Δλ3 ensures that the entire safe operating region is located in the steeper slope, preventing it from "lying flat" in the half-height section, thus maintaining a stable positive value for dα / dλ and high sensitivity. Secondly, as long as the first operating wavelength width is far from the half-height stop, it avoids the possibility of the operating band occasionally touching the flat region due to minor temperature fluctuations or measurement noise, which could lead to the derivative approaching zero and false alarms. A ratio less than or equal to 0.7 provides sufficient safety margin for the derivative sign reversal criterion, reducing false alarms and missed alarms.

[0074] In one optional embodiment of the present invention, the laser also has multiple gain operating curves at different temperatures, the multiple gain operating curves being gain curves when the laser is in an adjacent operating region; each gain operating curve has a first derivative of gain, and when the loss intensity is equal to the gain intensity, each first derivative of gain is equal to the first derivative of loss.

[0075] An optional embodiment of the present invention, such as Figure 2 As shown, each gain curve of the laser has a gain peak (λ). 增峰 α 增峰 ) and gain stop (λ) 增止 α 增止 The gain peak (λ) 增峰 α 增峰 () is the point on each gain operating curve where the gain intensity is maximum, and each gain peak has a gain peak wavelength λ. 增峰 and gain peak intensity α 增峰 The gain stop (λ) 增止 α 增止 The gain stop has a gain stop wavelength λ. 增止 and gain stop strength α 增止 Wherein, the gain stop strength α 增止 Equal to 0; each gain curve has a gain width, which is the gain peak wavelength λ. 增峰 With the gain stop wavelength λ 增止 The difference, wherein the gain bandwidth is greater than or equal to 10nm and less than or equal to 40nm.

[0076] An optional embodiment of the present invention, such as Figure 3 As shown, the laser also has an adjacent working reflectivity, which is the working reflectivity of the laser when it is in the adjacent working area, and the adjacent working reflectivity is greater than 0 and less than or equal to 0.1.

[0077] Specifically, such as Figure 3 As shown, point C corresponds to the half-height stop (λ3, α3) with a reflectivity of 25%, point B corresponds to the adjacent boundary point (λ2, α2) with a reflectivity of 10%, and point A corresponds to the loss peak point (λ1, α1).

[0078] In an optional embodiment of the present invention, when the laser is operating in the adjacent working area, the actual temperature T of the laser is... 实际 15℃ or higher and less than 70℃.

[0079] In one optional embodiment of the present invention, the laser further has a laser cavity length L, which is greater than or equal to 3 mm, and the warning threshold temperature T0 is greater than or equal to 70°C and less than or equal to 80°C. Specifically, a laser cavity length L greater than or equal to 3 mm is considered a long cavity design. If the loss-gain region of a short cavity and the loss-gain spectrum of a long cavity (greater than or equal to 3 mm) are placed on the same coordinate system, the overall curve of the short cavity will shift to the left. That is to say, the temperature at which Kink occurs in the short cavity is much higher than the temperature at which Kink is emitted in the long cavity. Therefore, Kink in the short cavity cannot be used for temperature warning because the Kink temperature is very high, and the laser device will be damaged when it reaches the Kink temperature of the short cavity. However, the Kink temperature of the long cavity is low. The principle of Kink occurrence at low temperatures (approximately 70°C-80°C) in the long cavity (greater than or equal to 3 mm) can be used for temperature measurement and warning. Therefore, at this low temperature, Kink will not damage the laser.

[0080] An optional embodiment of the present invention provides a laser that has the following characteristics in terms of loss, gain, intensity, and wavelength coordinates: the laser is a long-cavity laser, the cavity length L is greater than or equal to 3 mm, preferably greater than or equal to 4 mm, such as... Figure 1 As shown, the laser has a loss peak (λ1, α1) in the loss-gain-intensity-wavelength coordinate system. The loss peak (λ1, α1) is the point on the loss curve with the maximum loss intensity, and it has a loss peak wavelength λ1 and a loss peak intensity α1. It also has an adjacent boundary point (λ2, α2), which is the boundary point on the side of the adjacent working area furthest from the temperature warning zone. This adjacent boundary point has an adjacent boundary point wavelength λ2 and an adjacent boundary point loss intensity α2. The laser has a first operating wavelength ∆λ1, which is the difference between the loss peak wavelength λ1 and the adjacent boundary point wavelength λ2. The laser also has a first loss region, wherein, in the loss-gain intensity-wavelength coordinate system, the first loss region is adjacent to the adjacent working region on the side furthest from the temperature warning region; wherein, the loss curve of the first loss region has a half-maximum stop (λ3, α3), and the half-maximum stop has a first derivative equal to 0; the half-maximum stop has a half-maximum stop wavelength λ3 and a half-maximum stop loss intensity α3; the laser also has a half-maximum bandwidth ∆λ2, which is the difference between the loss peak wavelength λ1 and the half-maximum stop wavelength λ3. Wherein, the wavelength at the adjacent boundary point λ2 > 600 nm, the loss peak wavelength λ1 ≥ λ2 + 20 nm, and ∆λ2 / ∆λ1 ≤ 0.7. α2 < 2.5 cm -1 , α1≥1.5×α2.

[0081] In summary, the purpose of this invention is to provide a laser structure during the design and production of lasers that can designably and stably limit the kink phenomenon to occur within a temperature warning zone, where the maximum temperature of the warning zone is less than the failure temperature of the laser, thereby achieving an effective and identifiable warning mechanism and improving the operational reliability and safety of the laser.

[0082] In another aspect, this application also proposes a laser device comprising a laser as described above.

[0083] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0084] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0085] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0086] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A laser with its own failure warning function, characterized in that, The laser has a temperature warning zone, in which the laser experiences a kink phenomenon caused by longitudinal mode switching, and the kink phenomenon caused by longitudinal mode switching serves as a warning signal for the laser. The maximum temperature in the temperature warning zone is less than the failure temperature of the laser.

2. The laser according to claim 1, characterized in that, The laser has an adjacent working area, and the minimum temperature of the temperature warning area is greater than or equal to the maximum temperature of the adjacent working area.

3. The laser according to claim 2, characterized in that, The laser exhibits a kink phenomenon in the temperature warning zone, including: In the adjacent working area, any two adjacent working temperature points of the laser correspond to the same laser mode; In the temperature warning zone, the laser has at least one operating temperature point whose laser mode is different from the laser mode corresponding to the previous operating temperature point. The preceding working temperature point is located in the adjacent working area or the temperature warning area, and the difference between any two adjacent working temperature points is the same.

4. The laser according to claim 2, characterized in that, The laser exhibits a kink phenomenon in the temperature warning zone, including: In the adjacent working area, the difference in performance parameters between any two adjacent working temperature points of the laser is m. In the temperature warning zone, the laser has at least one operating temperature point whose performance parameter difference with the previous operating temperature point is n*m, where n≠1. Wherein, the previous operating temperature point is in the adjacent operating area or the temperature warning area, the difference between any two adjacent operating temperature points is the same, and the performance parameters include at least one of wavelength and output power.

5. The laser according to claim 3 or 4, characterized in that, The laser has a gain curve and a loss curve. The loss curve is the curve of the laser's loss intensity with respect to wavelength, and the gain curve is the curve of the laser's gain coefficient with respect to wavelength. In the adjacent working region, the first loss derivative of the loss intensity with respect to wavelength is greater than 0; In the temperature warning zone, the second first derivative of the loss intensity with respect to wavelength is less than 0.

6. The laser according to claim 5, characterized in that, The loss curve has a loss peak (λ1, α1), which is the point on the loss curve with the greatest loss intensity. The loss peak (λ1, α1) has a loss peak wavelength λ1 and a loss peak intensity α1. The adjacent working area is adjacent to the temperature warning area through the loss peak point (λ1, α1).

7. The laser according to claim 6, characterized in that, The loss curve has an adjacent boundary point (λ2, α2), which is the boundary point on the side of the adjacent working area away from the temperature warning area. The adjacent boundary point (λ2, α2) has an adjacent boundary point wavelength λ2 and an adjacent boundary point intensity α2. The laser has a first operating wavelength Δλ1, which is the difference between the loss peak wavelength λ1 and the adjacent boundary point wavelength λ2, and 20nm≤|Δλ1|≤40nm.

8. The laser according to claim 7, characterized in that, The first derivative of the first loss is greater than or equal to 0.5 cm. -1 / nm; The ratio of the loss peak intensity α1 to the adjacent boundary point intensity α2 is greater than or equal to 1.

5.

9. The laser according to claim 7, characterized in that, The laser also has a first loss region, which is adjacent to the adjacent working area on the side away from the temperature warning region. The loss curve in the first loss region includes a half-height stop (λ3, α3), which has a half-height stop wavelength λ3 and a half-height stop loss intensity α3. The first derivative of the half-height stop loss intensity α3 with respect to wavelength at the half-height stop (λ3, α3) is equal to 0. The laser also has a half-width at half maximum (WHM) Δλ2, which is the difference between the loss peak wavelength λ1 and the half-width at half maximum (WHM) stop wavelength λ3. Where, |△λ1| / |△λ2|≤0.

7.

10. The laser according to claim 5, characterized in that, The gain curve includes a gain peak (λ). 增峰 α 增峰 ) and gain stop (λ) 增止 ,0); The gain peak (λ) 增峰 α 增峰 It has a gain peak wavelength λ 增峰 and gain peak intensity α 增峰 ; The gain stop (λ) 增止 ,0) has a gain stop wavelength λ 增止 and gain stop strength 0; The gain curve has a gain width Δλ3, where Δλ3 is the gain peak wavelength λ. 增峰 With the gain stop wavelength λ 增止 The difference is 10nm≤|△λ3|<40nm.

11. The laser according to claim 1, 2, 3, 4, 6, 7, 8, 9 or 10, characterized in that, The laser also has a laser cavity length L, where L ≥ 3 mm.

12. The laser according to claim 11, characterized in that, The AR film layer of the laser has an adjacent working reflectivity of R in the adjacent working area, where 0 < R ≤ 0.

1.

13. The laser according to claim 12, characterized in that, The AR film is made of at least one of Al2O3, SiO2, SiN, Ta2O5, ZnS, ZnSe, HfO2 and TiO2.

14. The laser according to claim 1, 12, or 13, characterized in that, The difference between the maximum temperature in the temperature warning zone and the failure temperature of the laser is ΔT, where 5℃≤ΔT≤10℃.

15. A laser with its own failure warning function, characterized in that, The laser has an adjacent working area and a temperature warning area. The laser exhibits a kink phenomenon caused by longitudinal mode switching in the temperature warning area, and the kink phenomenon caused by longitudinal mode switching serves as a warning signal for the laser. Wherein, the maximum temperature of the temperature warning zone is less than the failure temperature of the laser, and the minimum temperature of the temperature warning zone is greater than or equal to the maximum temperature of the adjacent working zone; The laser has a gain curve and a loss curve. The loss curve is the curve of the laser's loss intensity with respect to wavelength, and the gain curve is the curve of the laser's gain coefficient with respect to wavelength. In the adjacent working region, the first first derivative of the loss intensity with respect to wavelength is greater than 0. In the temperature warning region, the second first derivative of the loss intensity with respect to wavelength is less than 0.

16. A laser device, characterized in that, The laser device includes a laser as described in any one of claims 1-15.

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