External cavity laser

Abstract

The utility model provides an external cavity laser, which is characterized in that a laser, an optical filtering assembly, a first reflecting device, a second reflecting device and a polarization maintaining optical fiber are sequentially arranged along a main optical path, a first detector is arranged on a reflecting optical path of the first reflecting device, and a second detector is arranged on a reflecting optical path of the second reflecting device. The first detector is used for receiving an optical signal reflected by the first reflecting device, and the second detector is used for receiving an optical signal reflected by the second reflecting device and calculating the wavelength of the optical signal; a third reflection device is arranged between the second reflection device and the second detector, a fourth reflection device is arranged on one side, back to the second detector, of the second reflection device, and the third reflection device and the fourth reflection device serve as resonant cavities to achieve the function of a standard component. The function of the light splitting device is realized through the first reflecting device and the second reflecting device, so that the light splitting device and the standard component are arranged on the main light path, and the integration level of the external cavity laser is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical devices, in particular to an external cavity laser. Background Art

[0002] With the rapid development of optical communication technology, the industry has higher and higher requirements for the communication density of optical modules, so the device size of optical modules is constantly shrinking. As an indispensable part of optical modules, external cavity tunable lasers also face size challenges. The reduction in size allows lasers and transmitters to be used in more occasions. However, the reduction in size will bring more challenges to the design of packaging components, which need to be integrated in a limited space without affecting the performance or reliability of the laser.

[0003] In an external cavity tunable laser, a wavelength locking component is usually required to accurately control the output wavelength of the laser. A general wavelength locking device usually uses a first spectrometer to transmit the optical signal output by the laser, and then uses a second spectrometer to separate the light separated by the first spectrometer again, one of which is received by a detector as a reference signal, and the other is received by another detector after passing through the FP standard. There is a clear correspondence between the intensity of the light filtered by the FP standard and the wavelength. The wavelength of the current optical signal is obtained by correlating the results of the two detectors, and finally the wavelength of the optical signal is locked by adjusting the optical filter. In the design of the above-mentioned external cavity tunable laser, multiple spectrometers and standards cannot be set in the main optical path, resulting in a larger overall size of the laser.

[0004] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology. Utility Model Content

[0005] The problem to be solved by the utility model is how to integrate the light splitting device and the etalon in the external cavity laser into the main optical path, so as to improve the integration degree of the external cavity laser.

[0006] In a first aspect, an external cavity laser is provided, comprising: a laser 1, an optical filter assembly 2, a first reflection device 3, a second reflection device 4 and a polarization-maintaining optical fiber 5 arranged in sequence along a main optical path, wherein the path of the optical signal emitted by the laser 1 is the main optical path;

[0007] A first detector 31 is arranged on the reflected light path of the first reflecting device 3; a second detector 32 is arranged on the reflected light path of the second reflecting device 4;

[0008] A third reflection device 6 is arranged between the second reflection device 4 and the second detector 32, and a fourth reflection device 7 is arranged on the side of the second reflection device 4 facing away from the second detector 32. The third reflection device 6 and the fourth reflection device 7 are both perpendicular to the direction of the reflected light signal of the second reflection device 4, and the third reflection device 6 and the fourth reflection device 7 serve as a resonant cavity.

[0009] Preferably, the optical filter assembly 2 comprises: a first etalon 21 and a second etalon 22, wherein:

[0010] The first etalon 21 and the second etalon 22 are arranged in sequence along the main optical path;

[0011] The first etalon 21 is used to receive the optical signal from the laser 1 , and the second etalon 22 is used to receive the optical signal from the first etalon 21 .

[0012] Preferably, the optical filter assembly 2 further includes: a phase adjustment module 23;

[0013] The phase adjustment module 23 is disposed between the first etalon 21 and the second etalon 22 .

[0014] Preferably, a first preset angle is formed between the first etalon 21 and the main optical path;

[0015] A second preset angle is formed between the second etalon 22 and the main optical path;

[0016] Wherein, the first preset angle and the second preset angle are both smaller than 90°.

[0017] Preferably, the end of the laser 1 facing away from the optical filter assembly 2 is coated with a high reflective film;

[0018] A fifth reflecting device 11 is further provided between the first reflecting device 3 and the optical filter assembly 2. The fifth reflecting device 11 is located on the main optical path, and the fifth reflecting device 11 is perpendicular to the direction of the main optical path.

[0019] The end of the laser 1 facing away from the optical filter assembly 2 and the fifth reflector 11 act together as a resonant cavity to achieve laser output.

[0020] Preferably, the external cavity laser comprises a first right-angled triangle prism 13, a second right-angled triangle prism 15 and a parallelogram prism 14, wherein:

[0021] The first right-angled triangle prism 13, the parallelogram prism 14, and the second right-angled triangle prism 15 are sequentially arranged along the main light path, the inclined surface of the first right-angled triangle prism 13 is in contact with one of the inclined surfaces of the parallelogram prism 14, and the other inclined surface of the parallelogram prism 14 is in contact with the inclined surface of the second right-angled triangle prism 15;

[0022] A partial reflection film is plated on the inclined surface between the first right triangle prism 13 and the parallelogram prism 14, which serves as the first reflection device 3;

[0023] A partial reflection film is plated on the inclined surface between the parallelogram prism 14 and the second right triangle prism 15, which serves as the second reflection device 4;

[0024] The bottom surface of the parallelogram prism 14 is coated with a partial reflection film, serving as the third reflection device 6;

[0025] The right-angled side of the second right-angled triangular prism 15 facing away from the second detector 32 is coated with a partial reflective film to serve as the fourth reflective device 7;

[0026] The right-angled side of the first right-angled triangular prism 13 facing the laser 1 is coated with a partial reflective film to serve as the fifth reflective device 11 .

[0027] Preferably, a collimating lens 8 is further provided on the main optical path, and the collimating lens 8 is located between the laser 1 and the optical filter assembly 2;

[0028] The collimating lens 8 is used to collimate the optical signal emitted by the laser 1 .

[0029] Preferably, an isolator 9 is further provided on the main optical path, and the isolator 9 is provided between the second reflector 4 and the polarization-maintaining optical fiber 5;

[0030] The isolator 9 is used to isolate external reflected light.

[0031] Preferably, a focusing lens 12 is further provided on the main optical path, and the focusing lens 12 is provided between the isolator 9 and the polarization-maintaining optical fiber 5;

[0032] The focusing lens 12 is used to focus the optical signal from the isolator 9 .

[0033] Preferably, the external cavity laser further comprises a thermoelectric cooler 10 , and the laser 1 , the optical filter assembly 2 , the first detector 31 and the second detector 32 are all arranged on the thermoelectric cooler 10 .

[0034] The utility model provides an external cavity laser, in which a laser 1, an optical filter assembly 2, a first reflection device 3, a second reflection device 4 and a polarization-maintaining optical fiber 5 are sequentially arranged along a main optical path, a first detector 31 is arranged on the reflection optical path of the first reflection device 3, and a second detector 32 is arranged on the reflection optical path of the second reflection device 4, the first detector 31 is used to receive an optical signal reflected by the first reflection device 3, and the second detector 32 is used to receive an optical signal reflected by the second reflection device 4, for calculating the wavelength of the optical signal; and a third reflection device 6 is arranged between the second reflection device 4 and the second detector 32, a fourth reflection device 7 is arranged on the side of the second reflection device 4 facing away from the second detector 32, the third reflection device 6 and the fourth reflection device 7 are used as a resonant cavity to realize the function of a standard component, and the function of a spectroscopic component is realized by the first reflection device 3 and the second reflection device 4, so that the spectroscopic component and the standard component are arranged on the main optical path, thereby improving the integration of the external cavity laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of the structure of an external cavity laser provided in an embodiment of the utility model;

[0037] Figure 2 A schematic diagram of the structure of another external cavity laser provided in an embodiment of the utility model;

[0038] Figure 3 A schematic diagram of the structure of another external cavity laser provided in an embodiment of the utility model;

[0039] Figure 4 A schematic structural diagram of a wavelength lock assembly in an external cavity laser provided in an embodiment of the utility model;

[0040] Figure 5 A schematic diagram of the structure of another external cavity laser provided in an embodiment of the utility model;

[0041] Figure 6 A top view of an optical filter assembly of an external cavity laser provided in an embodiment of the utility model;

[0042] Figure 7 A schematic diagram of the structure of another external cavity laser provided in an embodiment of the utility model;

[0043] The accompanying drawings are numbered as follows:

[0044] Laser 1; optical filter assembly 2; first etalon 21; second etalon 22; phase adjustment module 23; first reflector 3; first detector 31; second reflector 4; polarization-maintaining optical fiber 5; third reflector 6; fourth reflector 7; collimating lens 8; isolator 9; thermoelectric cooler 10; fifth reflector 11; focusing lens 12; first right-angled triangle prism 13; parallelogram prism 14; second right-angled triangle prism 15. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0046] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0047] In the description of the present utility model, the terms "first" and "second" are used for descriptive purposes only, and shall not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "multiple" is two or more. In addition, for example, the description may also use the method of adding "A" and "B" at the end to describe the same type of nouns as two independent individuals. In this case, the corresponding features defined as "A" and "B" are only used to distinguish the same type of individuals for description purposes, and shall not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0048] When describing some embodiments, the expressions "coupling", "coupling" and "connection" and their derivatives may be used. For example, when describing some embodiments, the term "connection" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupling" may be used to indicate that two or more components are in direct physical or electrical contact. However, the terms "connection" or "coupling" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other, such as "optical path coupling", "wireless connection", etc. The embodiments disclosed here are not necessarily limited to the contents of the present utility model.

[0049] In the description of the present utility model, "A and / or B" will be involved, wherein A and B are used to formally represent specific characteristic contents, and the corresponding expressions include the following three combinations: only A, only B, and a combination of A and B.

[0050] As used herein, “about,” “substantially,” or “approximately” includes the stated value and an average value that is within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity, i.e., the limitations of the measurement system.

[0051] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, it is not limited to that they can be carried in combination by one embodiment or example.

[0052] In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Embodiment 1:

[0054] Embodiment 1 of the present utility model provides an external cavity laser, such as Figure 1As shown, a laser 1, an optical filter assembly 2, a first reflection device 3, a second reflection device 4 and a polarization-maintaining optical fiber 5 are sequentially arranged along the main optical path, wherein the path of the optical signal emitted by the laser 1 is the main optical path.

[0055] like Figure 3 As shown, the first reflector 3 and the second reflector 4 are both at a preset angle with the main light path. The preset angle is set by those skilled in the art, and in this embodiment, the preset angle may be 45°.

[0056] In this embodiment, the laser 1 is used to emit an optical signal, the optical filter assembly 2 is used to select and adjust the frequency of the output optical signal, the first reflector 3 and the second reflector 4 can both reflect a portion of the optical signal in the main optical path, and can also transmit another portion of the optical signal in the main optical path, so that the other portion of the light continues to be transmitted along the main optical path, thereby realizing the function of the spectrometer.

[0057] like Figure 1 As shown, there is a first detector 31 on the reflected light path of the first reflecting device 3 , and the first detector 31 is used to receive the reflected light signal of the first reflecting device 3 .

[0058] The reflected light path of the first reflecting device 3 is the path of the reflected light signal after the first reflecting device 3 reflects the light signal on the main light path. The first detector 31 receives the reflected light signal of the first reflecting device 3 as a reference light signal, and the reference light signal is used for subsequent calculation of the wavelength frequency of the light signal.

[0059] like Figure 1 As shown, a second detector 32 is provided on the reflected light path of the second reflecting device 4 , and the second detector 32 is used for receiving the reflected light signal of the second reflecting device 4 .

[0060] The reflected light path of the second reflector 4 is the path of the reflected light signal after the second reflector 4 reflects the light signal on the main light path. The second detector 32 receives the reflected light signal of the second reflector 4 .

[0061] The preset angles between the first reflecting device 3 and the second reflecting device 4 and the main light path are set by those skilled in the art according to actual conditions, and are specifically set according to the positional relationship between the main light path and the first detector 31 and the second detector 32. In this embodiment, the preset angle may be 45°. Figure 1 As shown, at this time, the first detector 31 is arranged below the first reflecting device 3 , and the second detector 32 is arranged below the second reflecting device 4 .

[0062] like Figure 1As shown, a third reflection device 6 is arranged between the second reflection device 4 and the second detector 32, and a fourth reflection device 7 is arranged on the side of the second reflection device 4 facing away from the second detector 32. The third reflection device 6 and the fourth reflection device 7 are both perpendicular to the direction of the reflected light signal of the second reflection device 4, and the third reflection device 6 and the fourth reflection device 7 serve as a resonant cavity.

[0063] The third reflector 6 and the fourth reflector 7 together serve as an FP resonant cavity, wherein the path of the optical signal between the third reflector 6 and the fourth reflector 7 is as follows: the second reflector 4 reflects the optical signal on the main optical path toward the third reflector 6, and a part of the reflected optical signal is transmitted through the third reflector 6 and received by the second detector 32. Since the third reflector 6 and the fourth reflector 7 are perpendicular to the direction of the reflected optical signal of the second reflector 4, the third reflector 6 reflects another part of the optical signal reflected from the second reflector 4 back to the second reflector 4 along the original optical path, and transmits through the second reflector 4 to the second detector 32. Toward the fourth reflection device 7, the fourth reflection device 7 reflects the received optical signal along the original optical path back to the third reflection device 6, realizing the back and forth reflection of the optical signal between the third reflection device 6 and the fourth reflection device 7, and forming an FP resonant cavity. In the process of back and forth reflection, a part of the optical signal will be received by the second detector 32 through the third reflection device 6 in each back and forth reflection. The second detector 32 receives the above-mentioned optical signal from the FP resonant cavity and the optical signal from the second reflection device 4, thereby obtaining the relevant parameters of the wavelength of the optical signal, and calculates the wavelength of the optical signal through the relevant parameters of the wavelength of the optical signal and the reference optical signal.

[0064] The wavelength of the optical signal is adjusted by adjusting the optical filter component 2, and the actual wavelength of the optical signal is obtained by the first detector 31 and the second detector 32. Thus, the wavelength of the optical signal of the entire external cavity laser is adjusted to a preset value, and wavelength locking is achieved; while achieving the above effects, the first reflection device 3 and the second reflection device 4 for light splitting and the FP resonant cavity in this embodiment are all arranged on the main optical path, realizing the integrated structural design of the external cavity laser.

[0065] In summary, in this embodiment, the first reflection device 3, the second reflection device 4, the third reflection device 6, the fourth reflection device 7, the first detector 31 and the second detector 32 together serve as a wave lock component.

[0066] In order to ensure the normal operation of the external cavity laser, this embodiment needs to amplify the emitted optical signal through the resonant cavity, so this embodiment also includes the following design:

[0067] like Figure 1As shown, one end of the laser 1 facing away from the optical filter component 2 is coated with a high-reflection film; a fifth reflection device 11 is also arranged between the first reflection device 3 and the optical filter component 2, and the fifth reflection device 11 is located on the main optical path, and the fifth reflection device 11 is perpendicular to the direction of the main optical path; the end of the laser 1 facing away from the optical filter component 2 and the fifth reflection device 11 act together as a resonant cavity to realize laser output.

[0068] In this embodiment, considering that the first reflector 3, the second reflector 4, the third reflector 6, the fourth reflector 7, the first detector 31 and the second detector 32 are used together to calculate and measure the wavelength of the optical signal, that is, they are used together as wavelength locking devices, so this embodiment provides a structural design, integrating the first reflector 3, the second reflector 4, the third reflector 6, the fourth reflector 7 and the fifth reflector 11 into a plurality of prisms, and cooperating with the plurality of prisms to serve as a wavelength locking component, such as Figure 2 As shown, the corresponding structure is designed as follows:

[0069] The external cavity laser comprises a first right-angled triangle prism 13, a second right-angled triangle prism 15 and a parallelogram prism 14, wherein:

[0070] like Figure 2 As shown, the first right-angled triangle prism 13, the parallelogram prism 14 and the second right-angled triangle prism 15 are arranged in sequence along the main light path, the inclined surface of the first right-angled triangle prism 13 is in contact with one of the inclined surfaces of the parallelogram prism 14, and the other inclined surface of the parallelogram prism 14 is in contact with the inclined surface of the second right-angled triangle prism 15.

[0071] like Figure 2 As shown, in this embodiment, the angle between the hypotenuse and the right angle side of the first right-angled triangular prism 13 and the second right-angled triangular prism 15 can be 45°.

[0072] like Figure 2-Figure 4 As shown, a partial reflection film is coated on the inclined surface between the first right-angled triangle prism 13 and the parallelogram prism 14, as the first reflection device 3. The partial reflection film coated on the inclined surface between the first right-angled triangle prism 13 and the parallelogram prism 14 can be a 1% reflection film. Further, the partial reflection film can be coated only on the inclined surface of the first right-angled triangle prism 13, the partial reflection film can be coated only on the corresponding inclined surface of the parallelogram prism 14, or the partial reflection film can be coated on both the inclined surface of the first right-angled triangle prism 13 and the corresponding inclined surface of the parallelogram prism 14.

[0073] like Figure 2-Figure 4As shown, in this embodiment, the first detector 31 is arranged below the first right-angled triangle prism 13 and is located on the reflected light path of the first reflecting device 3; it should be noted that in order to prevent the upper end face of the parallelogram prism 14 and the lower end face of the first right-angled triangle prism 13 from reflecting light signals back and forth to form a resonant cavity, an anti-reflection film is coated on the upper end face of the parallelogram prism 14 and the lower end face of the first right-angled triangle prism 13 to prevent the formation of a resonant cavity.

[0074] like Figure 2-Figure 4 As shown, a partial reflection film is coated on the inclined surface between the parallelogram prism 14 and the second right-angled triangle prism 15, as the second reflection device 4. The partial reflection film coated on the inclined surface between the parallelogram prism 14 and the second right-angled triangle prism 15 can be a 1% reflection film. Further, the partial reflection film can be coated only on the inclined surface of the second right-angled triangle prism 15, the partial reflection film can be coated only on the corresponding inclined surface of the parallelogram prism 14, or the partial reflection film can be coated on both the inclined surface of the second right-angled triangle prism 15 and the corresponding inclined surface of the parallelogram prism 14.

[0075] like Figure 2-Figure 4 As shown, in this embodiment, the second detector 32 is arranged below the lower end surface of the parallelogram prism 14 and is located on the reflection light path of the second reflection device 4.

[0076] like Figure 2-Figure 4 As shown, the bottom surface of the parallelogram prism 14 is coated with a partial reflection film as the third reflection device 6. The partial reflection film coated on the bottom surface of the parallelogram prism 14 can be a 50% reflection film.

[0077] like Figure 2-Figure 4 As shown, the right-angled side of the second right-angled triangular prism 15 away from the second detector 32 is coated with a partial reflective film as the fourth reflective device 7. The partial reflective film coated on the right-angled side of the second right-angled triangular prism 15 away from the second detector 32 may be a 50% reflective film.

[0078] The fourth reflection device 7 and the third reflection device 6 serve as a FP resonant cavity.

[0079] like Figure 2-Figure 4 As shown, the right-angled side of the first right-angled triangular prism 13 facing the laser 1 is coated with a partial reflective film to serve as the fifth reflective device 11 .

[0080] In this embodiment, the optical filter assembly 2 needs to adjust the wavelength and frequency of the optical signal emitted by the laser 1, so a corresponding FP standard tool is required. Therefore, this embodiment involves the following design:

[0081] like Figure 5 As shown, the optical filter assembly 2 includes: a first etalon 21 and a second etalon 22, wherein:

[0082] The first etalon 21 and the second etalon 22 are sequentially arranged along the main optical path; the first etalon 21 is used to receive the optical signal from the laser 1 , and the second etalon 22 is used to receive the optical signal from the first etalon 21 .

[0083] like Figure 5 As shown, in this embodiment, the first etalon 21 and the second etalon 22 are both FP etalons, wherein the first etalon 21 and the second etalon 22 have different free spectral ranges, for example, the free spectral range of the first etalon 21 is FSR1, and the free spectral range of the second etalon 22 is FSR2. By using the vernier effect, the joint free spectral range of the filter assembly can be expressed as: JFSR=(FSR1*FSR2) / (FSR1-FSR2), wherein JFSR is the joint free spectral range of the filter assembly, so that the wavelength tunable range of the entire external cavity laser is the joint free spectral range, thereby realizing a wide range of tunable wavelength of the optical signal.

[0084] There is a first preset angle between the first etalon 21 and the main light path; there is a second preset angle between the second etalon 22 and the main light path; wherein the first preset angle and the second preset angle are both less than 90°.

[0085] like Figure 6 As shown, Figure 6 FIG. 1 is a top view of the optical filter assembly 2. In order to prevent the first standard component and the second standard component from generating light reflected back along the original optical path when receiving the optical signal, which may affect the entire external cavity laser, the first standard tool 21 and the main optical path are at a first preset angle, and the second standard tool 22 and the main optical path are at a second preset angle. Figure 6 The middle dotted line is the main light path. In this embodiment, the first preset angle and the second preset angle are both set by those skilled in the art, and the first preset angle and the second preset angle are not equal to 90°.

[0086] After achieving the above-mentioned large-range adjustment of the optical signal, it is also necessary to achieve small-range adjustment of the optical signal, that is, fine adjustment, so the following designs are also involved:

[0087] like Figure 5As shown, the optical filter assembly 2 further includes: a phase adjustment module 23 ; the phase adjustment module 23 is arranged between the first etalon 21 and the second etalon 22 .

[0088] In this embodiment, both sides of the phase adjustment module 23 are coated with anti-reflection films to prevent the phase adjustment module 23 from generating reflected light when receiving an optical signal. The phase adjustment module 23 is used to achieve fine adjustment of the wavelength of the optical signal in a small range.

[0089] It should be noted that, in this embodiment, it is necessary to adjust the temperature of the first etalon 21 , the second etalon 22 and the phase adjustment module 23 so as to perform coarse or fine adjustment on the wavelength of the optical signal.

[0090] It is worth mentioning that in order to realize normal optical signal transmission and reception of the external cavity laser in this embodiment, this embodiment also involves the structural design of the following components:

[0091] like Figure 7 As shown, a collimating lens 8 is also provided on the main optical path, and the collimating lens 8 is located between the laser 1 and the optical filter assembly 2 ; the collimating lens 8 is used to collimate the optical signal emitted by the laser 1 .

[0092] like Figure 7 As shown, an isolator 9 is also provided on the main optical path, and the isolator 9 is provided between the second reflector 4 and the polarization-maintaining optical fiber 5; the isolator 9 is used to isolate the external reflected light.

[0093] like Figure 7 As shown, a focusing lens 12 is also provided on the main optical path, and the focusing lens 12 is provided between the isolator 9 and the polarization-maintaining optical fiber 5; the focusing lens 12 is used to focus the optical signal from the isolator 9 so that the polarization-maintaining optical fiber 5 receives the focused optical signal.

[0094] like Figure 7 As shown, in this embodiment, in order to achieve control and regulation of the temperature of the entire external cavity laser, multiple corresponding components are arranged in the thermoelectric cooler 10 in this embodiment, and the specific design is as follows:

[0095] like Figure 7 As shown, the laser 1 , the optical filter assembly 2 , the first detector 31 and the second detector 32 are all arranged on the thermoelectric cooler 10 .

[0096] like Figure 7 As shown, in addition to the above components, a collimating lens 8 , an optical isolator 9 and a focusing lens 12 are also provided on the thermoelectric cooler 10 .

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An external cavity laser, characterized in that: include: A laser (1), an optical filter assembly (2), a first reflector (3), a second reflector (4) and a polarization-maintaining optical fiber (5) are arranged in sequence along a main optical path, wherein the path of the optical signal emitted by the laser (1) is the main optical path; A first detector (31) is provided on the reflected light path of the first reflecting device (3); and a second detector (32) is provided on the reflected light path of the second reflecting device (4); A third reflecting device (6) is arranged between the second reflecting device (4) and the second detector (32); a fourth reflecting device (7) is arranged on the side of the second reflecting device (4) facing away from the second detector (32); the third reflecting device (6) and the fourth reflecting device (7) are both perpendicular to the direction of the reflected light signal of the second reflecting device (4); and the third reflecting device (6) and the fourth reflecting device (7) serve as a resonant cavity.

2. The external cavity laser according to claim 1, characterized in that: The optical filter assembly (2) comprises: a first etalon (21) and a second etalon (22), wherein: The first etalon (21) and the second etalon (22) are arranged in sequence along the main optical path; The first etalon (21) is used to receive an optical signal from a laser (1), and the second etalon (22) is used to receive an optical signal from the first etalon (21).

3. The external cavity laser according to claim 2, characterized in that: The optical filter component (2) further comprises: a phase adjustment module (23); The phase adjustment module (23) is arranged between the first etalon (21) and the second etalon (22).

4. The external cavity laser according to claim 2, characterized in that: A first preset angle is formed between the first etalon (21) and the main optical path; A second preset angle is formed between the second etalon (22) and the main optical path; Wherein, the first preset angle and the second preset angle are both smaller than 90°.

5. The external cavity laser according to claim 1, characterized in that: One end of the laser (1) facing away from the optical filter component (2) is coated with a high-reflection film; A fifth reflecting device (11) is further provided between the first reflecting device (3) and the optical filter assembly (2), the fifth reflecting device (11) being located on the main optical path, and the fifth reflecting device (11) being perpendicular to the direction of the main optical path; One end of the laser (1) facing away from the optical filter assembly (2) and the fifth reflector (11) act together as a resonant cavity to achieve laser output.

6. The external cavity laser according to claim 5, characterized in that: The external cavity laser comprises a first right-angled triangle prism (13), a second right-angled triangle prism (15) and a parallelogram prism (14), wherein: The first right-angled triangular prism (13), the parallelogram prism (14), and the second right-angled triangular prism (15) are arranged in sequence along the main light path; the inclined surface of the first right-angled triangular prism (13) is in contact with one of the inclined surfaces of the parallelogram prism (14); and the other inclined surface of the parallelogram prism (14) is in contact with the inclined surface of the second right-angled triangular prism (15); A partial reflection film is plated on the inclined surface between the first right-angled triangle prism (13) and the parallelogram prism (14) that are in contact with each other, serving as the first reflection device (3); A partial reflection film is plated on the inclined surface between the parallelogram prism (14) and the second right-angled triangle prism (15) that is in contact with each other, serving as the second reflection device (4); The bottom surface of the parallelogram prism (14) is coated with a partial reflection film, serving as the third reflection device (6); The right-angled side of the second right-angled triangular prism (15) facing away from the second detector (32) is coated with a partial reflective film to serve as the fourth reflective device (7); The right-angled side of the first right-angled triangular prism (13) facing the laser (1) is coated with a partial reflective film to serve as the fifth reflective device (11).

7. The external cavity laser according to claim 1, characterized in that: A collimating lens (8) is also provided on the main optical path, and the collimating lens (8) is located between the laser (1) and the optical filter assembly (2); The collimating lens (8) is used to collimate the optical signal emitted by the laser (1).

8. The external cavity laser according to claim 1, characterized in that: An isolator (9) is also provided on the main optical path, and the isolator (9) is provided between the second reflector (4) and the polarization-maintaining optical fiber (5); The isolator (9) is used to isolate external reflected light.

9. The external cavity laser according to claim 8, characterized in that: A focusing lens (12) is also provided on the main optical path, and the focusing lens (12) is provided between the isolator (9) and the polarization-maintaining optical fiber (5); The focusing lens (12) is used to focus the optical signal from the isolator (9).

10. The external cavity laser according to claim 1, characterized in that: The external cavity laser further comprises a thermoelectric cooler (10), and the laser (1), the optical filter assembly (2), the first detector (31) and the second detector (32) are all arranged on the thermoelectric cooler (10).

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