Tunable laser array

Abstract

The utility model provides a tunable laser array. The tunable laser array comprises a gain chip array (101), a lens array (102), a wavelength tuning assembly (103), a wavelength locking assembly (104), an isolation assembly (105), an output optical fiber assembly (106), a thermistor (107) and a TEC (108). The gain chip array (101) comprises a plurality of gain chips, emergent light of the gain chips passes through the lens array (102) to form collimated light beams to be output, the collimated light beams are subjected to laser wavelength mode selection through the wavelength tuning assembly (103), then sequentially pass through the wavelength locking assembly (104) and the isolation assembly (105) and are finally coupled to the output optical fiber group 206, and laser output is completed. According to the technical scheme, integration of a plurality of wide-range narrow-linewidth tunable lasers can be achieved, a tunable laser array is formed, and assembling of downstream products is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of optoelectronic module packaging technology, and in particular to tunable laser arrays. Background Technology

[0002] Currently, hyperscale data centers primarily utilize 400G / 800G / 1.6T pluggable optical modules. To achieve greater capacity and higher integration, the industry is developing optical interfaces using Co-packaged Optics (CPO) technology, which is fundamentally different from current optical module interfaces. CPO is a packaging technology that co-packages the optical module and the ASIC switching chip onto a board with the smallest possible area. By shortening the distance between the switching chip and the optical engine, the transmission speed of electrical signals between the chip and the engine is significantly improved. However, due to the high power consumption and heat dissipation of the switching chip, and the extreme temperature sensitivity of the InP-based laser source, placing the laser source too close to the heat source of the switching chip will inevitably lead to a decrease in the reliability of the light source itself and will also hinder the heat dissipation of the switching chip. A better solution is to independently package the laser source, retaining only the silicon photonics IC (PIC), which is insensitive to temperature changes, for close connection with the switching chip, thereby significantly improving the system's reliability and maintainability.

[0003] For the specific implementation of external light sources (ELS), if EML or DFB lasers are used in the same way as internal light sources, the inability to change the output wavelength of either EML or DFB lasers will severely limit the ability of the switch to be continuously expanded and upgraded. Furthermore, as the number of wavelengths increases, the manufacturing cost of EML / DFB lasers for different wavelengths also increases dramatically. To avoid these problems, using tunable lasers as external light sources has become a more ideal choice. However, current tunable lasers are complex to manufacture, and are generally packaged as single light sources. Simply stacking multiple tunable lasers results in a very large external light source, which in turn affects the package size of subsequent modules. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a tunable laser array that integrates multiple wide-range, narrow-linewidth tunable lasers to form a tunable laser array, which facilitates the assembly of downstream products.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a tunable laser array, including a gain chip array (101), a lens array (102), a wavelength tuning component (103), a wavelength locking component (104), an isolation component (105), an output fiber component (106), a thermistor (107), and a TEC (108); the gain chip array (101) includes multiple gain chips, and the light emitted from the gain chips passes through the lens array (102) to form a collimated beam output. The collimated beam passes through the wavelength tuning component (103) for laser wavelength mode selection, and then passes through the wavelength locking component (104) and the isolation component (105) in sequence, and finally couples to the output fiber group 206 to complete the laser output; the wavelength locking component (104) is used to monitor the wavelength shift of multiple laser beams; the gain chip array (101), the lens array (102), and the wavelength tuning component (103) form a laser resonant cavity; the isolation component (105) is used to prevent the output light from being reflected or external light from entering the laser resonant cavity.

[0006] In a preferred embodiment, the wavelength tuning component (103) includes 2*N tunable filter elements for laser mode selection via the vernier effect, where N represents the number of gain chips.

[0007] In a preferred embodiment, the wavelength locking component (104) includes a beam splitter (11), a first power detection group (12), an optical etalon (13), and a second power detection group (14); the beam splitter (11), the optical etalon (13), and the second power detection group (14) are arranged sequentially along the incident direction of the laser beam; the first power detection group (12) is located at the bottom of the beam splitter (11).

[0008] In a preferred embodiment, the number of optical etalons (13) is one.

[0009] In a preferred embodiment, the first power detection group (12) includes N photodetectors for collecting N laser power, and the second power detection group (14) includes N photodetectors for collecting the transmission spectral power of N lasers through the optical etalon (13).

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1) To achieve the integration of multiple wide-range narrow-linewidth tunable lasers to form a tunable laser array, which facilitates the assembly of downstream products.

[0012] 2) An innovative wavelength locking scheme is adopted, which can lock the wavelengths of multiple lasers of different wavelengths with only one optical etalon, reducing the complexity of laser array wavelength locking.

[0013] 3) Compared to the technical solution of simply stacking and assembling multiple tunable lasers, the product cost and packaging size can be significantly reduced due to the shared use of the product housing, semiconductor cooling chip (TEC), PCBA board and some electronic components. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a tunable laser array according to a preferred embodiment of the present invention;

[0015] Figure 2 This is a structural diagram of the wavelength locking component according to a preferred embodiment of the present invention.

[0016] Figure reference numerals: 101-Gain chip array, 102-Lens array, 103-Wavelength tuning component, 104-Wavelength locking component, 105-Isolation component, 106-Output fiber optic component, 107-Thermistor, 108-TEC. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] refer to Figures 1-2The tunable laser array includes a gain chip array 101, a lens array 102, a wavelength tuning component 103, a wavelength locking component 104, an isolation component 105, an output fiber assembly 106, a thermistor 107, and a thermoelectric cooler TEC 108. The gain chip array 101 includes multiple gain chips. The light emitted from the gain chips is collimated by the lens array 102, then sequentially passes through the wavelength tuning component 103, the wavelength locking component 104, and the isolation component 105, finally coupling to the output fiber assembly 106 to complete the laser output. The wavelength tuning component 103 contains 2*N tunable filter elements for laser mode selection via the vernier effect, where N represents the number of gain chips. The number of laser beams in the tunable laser array corresponds one-to-one with the number of gain chips (1:1). The number of laser beams corresponds to the number of photodetectors (1:2), meaning one laser beam requires two photodetectors. In this patent, the laser beams are divided into two groups (power detection groups), therefore the number of photodetectors in each group also corresponds to the number of laser beams (1:1). Wavelength locking component 104 is used for wavelength drift monitoring of multiple laser beams; isolation component 105 is used to achieve unidirectional optical path passage and prevent light from the output line from being reflected back into the external cavity laser. The semiconductor cooler TEC 108 and the thermistor 107, which collects the resistance value, form a closed-loop control to achieve overall temperature control within the laser. Compared to existing tunable lasers, this novel tunable laser array, while increasing the required number of gain chips, wavelength tuning elements, and output fiber components proportionally, shares the same components for the wavelength locking component, isolation component, TEC, thermistor, packaging housing, and circuit board, thereby significantly reducing product costs.

[0021] The wavelength locking assembly 104 includes a beam splitter 11, a first power detection group 12, an optical etalon 13, and a second power detection group 34. It also includes a temperature control component for independently controlling the temperature of the optical etalon 13. In this embodiment, the temperature control component is a heating resistor. Multiple laser beams incident parallel to the wavelength locking assembly 104 (…) Figure 2(Illustrated only for one path) After passing through beam splitter 11, more than 90% of the light will directly pass through the first beam splitting surface of beam splitter 11 and be output as the first sub-beam 1. Less than 10% of the light is reflected from the first beam splitting surface and then incident on the second beam splitting surface of beam splitter 11, where it is further split into a transmitted second sub-beam 2 and a reflected third sub-beam 3. The power values ​​of both the second sub-beam 2 and the third sub-beam 3 are less than 5% of the original incident power. The second sub-beam 2 is directly incident on the first power detection group 12, while the third sub-beam 3 passes through the optical etalon 13 and then is incident on the second power detection group 14. Both the first power detection group 13 and the second power detection group 14 contain multiple photodetectors for collecting the optical power of the second sub-beam 2 and the third sub-beam 3 of the multiple laser beams. By combining the transmission spectrum curve of the optical etalon 13, wavelength locking can be performed on each incident laser beam (the wavelength locking principle is a well-known technology in the industry and will not be elaborated here). Unlike industry-standard solutions, the wavelength locking component 104 of this invention uses only one optical etalon 13 to simultaneously lock the wavelengths of multiple laser beams of different wavelengths, thereby reducing the number of optical etalons required. In particular, optical etalons typically require independent temperature control; reducing the number of optical etalons will simultaneously reduce the number of temperature control components, thus significantly reducing the complexity and cost of the module.

Claims

1. A tunable laser array, characterized in that, The system includes a gain chip array (101), a lens array (102), a wavelength tuning component (103), a wavelength locking component (104), an isolation component (105), an output fiber component (106), a thermistor (107), and a TEC (108). The gain chip array (101) includes multiple gain chips. The light emitted from the gain chips passes through the lens array (102) to form a collimated beam output. The collimated beam passes through the wavelength tuning component (103) for laser wavelength mode selection, and then passes through the wavelength locking component (104) and the isolation component (105) in sequence. Finally, it is coupled to the output fiber group (206) to complete the laser output. The wavelength locking component (104) is used to monitor the wavelength shift of multiple laser beams. The gain chip array (101), the lens array (102), and the wavelength tuning component (103) form a laser resonant cavity. The isolation component (105) is used to prevent the output light from being reflected or external light from entering the laser resonant cavity.

2. The tunable laser array according to claim 1, characterized in that, The wavelength tuning component (103) contains 2*N tunable filter elements for laser mode selection via the vernier effect, where N represents the number of gain chips.

3. The tunable laser array according to claim 1, characterized in that, The wavelength locking assembly (104) includes a beam splitter (11), a first power detection group (12), an optical etalon (13), and a second power detection group (14); the beam splitter (11), the optical etalon (13), and the second power detection group (14) are arranged sequentially along the incident direction of the laser beam; the first power detection group (12) is located at the bottom of the beam splitter (11).

4. The tunable laser array according to claim 3, characterized in that, The number of optical etalons (13) is 1.

5. The tunable laser array according to claim 3, characterized in that, The first power detection group (12) contains N photodetectors for collecting N laser power, and the second power detection group (14) contains N photodetectors for collecting the transmission spectral power of N lasers through the optical etalon (13).

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