Optical modulation chip and wavelength tunable laser

Abstract

To provide an optical modulation chip and a wavelength variable laser.SOLUTION: An optical modulation chip 100 includes: an electro-optical phase modulation module 110 for modulating the wavelength of an input laser beam on the basis of an electro-optical effect and a target wavelength mode; and a passage bandwidth module 120 for receiving a laser beam output by the electro-optical phase modulation module, reflecting at least a part of laser beams in the target wavelength mode of the input laser beams, outputting the laser beams, and diffusing a laser beam other than the laser beams out of the target wavelength mode of the input laser beams.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to the technical field of lasers, and in particular to optical modulation chips and tunable lasers. [Background technology]

[0002] A tunable laser is a laser whose laser output wavelength can be continuously varied within a specific range. Such lasers have a wide range of applications and may be used in spectroscopy, photochemistry, medicine, biology, integrated optics, pollution monitoring, semiconductor material processing, information processing, communications, etc.

[0003] The implementation technologies for tunable lasers can be classified into current-controlled, temperature-controlled, and mechanical-controlled technologies. Current-controlled tunable lasers can achieve wavelength tuning by changing the injection current and have nanosecond-level tuning speeds, relatively wide tuning bandwidths, but low output powers. Such lasers mainly include sampled-grating distributed Bragg reflector (SG-DBR) lasers and grating-assisted codirectional coupler with rear-sampled-grating reflector (GCSR) lasers. Temperature-controlled tunable lasers can change the laser output wavelength by changing the refractive index of the laser's active region, which is a simple technique but has the characteristics of slow speeds and narrow tuning bandwidths (generally only a few nanometers). Such lasers mainly include distributed feedback (DFB) lasers and distributed Bragg reflector (DBR) lasers. Mechanically controlled tunable lasers mainly rely on microelectromechanical systems (MEMS) technology to achieve wavelength selection and have relatively large tuning bandwidths and relatively high output powers. Such lasers mainly include distributed feedback (DFB) lasers, external cavity lasers (ECLs), and vertical cavity surface emitting lasers (VCSELs).

[0004] For tunable lasers based on current control technology, how to enable tunable lasers to have increased modulation speed and improved operation performance is an urgent technical problem to be solved. Summary of the Invention

[0005] Embodiments of the present disclosure provide an optical modulation chip and a tunable laser to enable the tunable laser to have increased modulation speed and improved operating performance.

[0006] According to one aspect of the present disclosure, an optical modulation chip is provided that includes an electro-optic phase modulation module configured to modulate the wavelength of input laser light based on an electro-optic effect and a target wavelength mode, and a passband module configured to receive the laser light output by the electro-optic phase modulation module, reflect and then output at least a portion of the laser light input thereto that is in the target wavelength mode, and dissipate the laser light input thereto that is outside the target wavelength mode.

[0007] In some embodiments, the passband module is configured as a fixed passband module having an operating passband that cannot be modulated, or the passband module is configured as an electro-optic passband modulation module having an operating passband that can be modulated based on the electro-optic effect.

[0008] In some embodiments, the passband module is configured as a passband grating module.

[0009] In some embodiments, the passband module is configured as a distributed Bragg reflector passband grating module.

[0010] In some embodiments, the optical modulation chip further includes a gain medium configured to optically amplify laser light input thereto.

[0011] In some embodiments, the optical modulation chip further includes a reflecting module configured to reflect laser light directed thereto in a target wavelength mode toward a target module and to reflect laser light directed thereto that is outside the target wavelength mode out of the target module, the target module being a gain medium or an electro-optic phase modulation module.

[0012] In some embodiments, the reflector module is configured as a fixed wavelength reflector module having an operating wavelength that cannot be modulated, at which laser light is reflected to the target module, or the reflector module is configured as an electro-optical reflector modulation module having an operating wavelength that can be modulated based on the electro-optic effect, at which laser light is reflected to the target module.

[0013] In some embodiments, the optical modulation chip includes a sequentially arranged reflection module, a gain medium, an electro-optic phase modulation module, and a passband module, or the optical modulation chip includes a sequentially arranged reflection module, an electro-optic phase modulation module, a gain medium, and a passband module.

[0014] In some embodiments, the electro-optic phase modulation module includes a strip waveguide and a waveguide electrode for applying an electric field to the strip waveguide, and / or a ring resonator waveguide and a waveguide electrode for applying an electric field to the ring resonator waveguide.

[0015] According to one aspect of the present disclosure, there is provided a tunable laser including the optical modulation chip of the aforementioned aspect.

[0016] According to one or more embodiments of the present disclosure, the optical modulation chip modulates the wavelength of the input laser light based on an electro-optic phase modulation module, thereby enabling the tunable laser to have a faster modulation speed, thereby significantly improving the operating performance of the tunable laser.

[0017] It should be understood that the contents described in this section are not intended to identify critical or important features of the embodiments of the present disclosure, and are not intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will be readily apparent from the following description.

[0018] Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments, with reference to the accompanying drawings. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram of a simplified structure of an optical modulation chip according to some exemplary embodiments of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of a simplified structure of an optical modulation chip according to some exemplary embodiments of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram of a simplified structure of an optical modulation chip according to some exemplary embodiments of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram of a simplified structure of an optical modulation chip according to some exemplary embodiments of the present disclosure. [Figure 5] FIG. 5 is a schematic diagram of a simplified structure of an optical modulation chip according to some exemplary embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0020] Only a few exemplary embodiments are briefly described below. As will be understood by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Accordingly, the accompanying drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.

[0021] Although most tunable lasers are required to output laser light in a single wavelength mode, lasers with a fixed cavity length can have multiple wavelength modes. When the cavity length of the laser is equal to an integer multiple of the effective wavelength, this mode can be maintained in a stable state for wavelengths that are integer multiples of the effective wavelength. Typically, when designing a tunable laser structure, the tunable laser structure is generally designed based on the laser light in a target wavelength mode and designed to have minimum loss. Then, to achieve the goal of outputting laser light in a single wavelength mode, the laser light in the target wavelength mode is optically amplified and the laser light in other wavelength modes is rejected.

[0022] In the related art, tuning of laser light by a wavelength tunable laser is mostly achieved by modulating the passband of the reflection and transmission regions based on the thermo-optic effect, and the modulation speed is not ideal.

[0023] Embodiments of the present disclosure provide an optical modulation chip and a tunable laser to enable the tunable laser to have increased modulation speed and improved operating performance.

[0024] As shown in FIG. 1 , in some embodiments of the present disclosure, an optical modulation chip 100 includes an electro-optic phase modulation module 110 and a passband module 120, where the electro-optic phase modulation module 110 is configured to modulate the wavelength of laser light input thereto based on the electro-optic effect and a target wavelength mode (such as λ), and the passband module 120 is configured to receive the laser light output by the electro-optic phase modulation module 110, reflect and then output at least a portion of the laser light input thereto that is in the target wavelength mode, and dissipate the laser light input thereto that is outside the target wavelength mode.

[0025] For example, as shown in FIG. 1, the wavelength of the laser light input into the optical modulation chip 100 through the gain medium 130 can include various modes such as λ0, λ1, and λ2, and assuming that the target wavelength mode is λ0 and the reflection ratio of the passband module 120 is r (r is less than 1), the passband module 120 should continuously reflect the light having the wavelength mode of λ0 with a reflection ratio of r, and thus the light enters the gain medium 130 for amplification, and a small portion of this light having the wavelength mode of λ0 is output, and the light having the wavelength modes of λ1 and λ2 is dissipated by the passband module 120.

[0026] The electro-optic phase modulation module 110 is fabricated based on the electro-optic effect of electro-optic materials. The electro-optic effect refers to the fact that when a voltage is applied to an electro-optic material, such as a lithium niobate crystal, a gallium arsenide crystal, or a lithium tantalate crystal, the refractive index of the electro-optic material fluctuates, resulting in changes in the properties of the light wave passing through the electro-optic material. The use of the electro-optic effect allows for modulation of parameters such as the phase, amplitude, intensity, and polarization state of an optical signal.

[0027] Compared with the related art, the optical modulation chip 100 according to the embodiment of the present disclosure modulates the wavelength of the input laser light based on the electro-optic phase modulation module 110, thereby enabling the tunable laser to have a faster modulation speed, thereby significantly improving the operating performance of the tunable laser.

[0028] In some embodiments of the present disclosure, the electro-optic phase modulation module 110 includes a strip waveguide 11 and a waveguide electrode 13 for applying an electric field to the strip waveguide 11. In addition, the electro-optic phase modulation module 110 may further include a ring resonator waveguide 12 and a waveguide electrode 13 for applying an electric field to the ring resonator waveguide 12 (see FIG. 5 ).

[0029] The strip waveguide 11 has a simple structure, and a strip ridge waveguide, for example, may be used. The ring resonator is a traveling-wave resonant cavity, and laser light propagates in the resonant cavity in a traveling-wave mode. This overcomes the spatial hole burning effect common in linear resonators, and the output power is high. The ring resonator is designed to have a specific wavelength mode, and only laser light of the specific wavelength mode can be output through the ring resonator. The corresponding wavelength mode can be obtained by modulation by applying an electric field to the electro-optical material waveguide by the waveguide electrode 13.

[0030] In embodiments of the present disclosure, passband module 120 may be configured as a fixed passband module having an operating passband that cannot be modulated, or as an electro-optic passband modulation module having an operating passband that can be modulated based on the electro-optic effect. When passband module 120 is an electro-optic passband modulation module, the electro-optic passband modulation module is fabricated based on the electro-optic effect of an electro-optic material, and its operating passband may be adjusted under the control of passband electrodes 21.

[0031] In an embodiment of the present disclosure, the passband module 120 may be configured as a passband grating module, such as a distributed Bragg reflector (DBR) passband grating module. A DBR is a periodic structure composed of two alternating layers of materials with different refractive indices, with each layer having an optical thickness of 1 / 4 of the center reflection wavelength. Because electromagnetic waves with frequencies within the energy gap cannot be transmitted, the reflectivity of a DBR can reach 99% or more. Furthermore, there is no absorption problem in metallic mirrors, and the position of the energy gap can be adjusted by changing the refractive index or thickness of the material.

[0032] 1 , the gain medium 130 may not be included within the optical modulation chip 100, and the input end of the optical modulation chip 100 is optically coupled to the gain medium 130. The gain medium 130 is configured to optically amplify laser light input thereto. In laser physics, a gain medium refers to a medium capable of amplifying optical power (generally in the form of a beam).

[0033] As shown in FIG. 2, in some embodiments, the gain medium 130 may also be included within the structure of the optical modulation chip 100, i.e., the gain medium 130 is integrated within the structure of the optical modulation chip 100.

[0034] As shown in FIG. 2 , in some embodiments of the present disclosure, the optical modulation chip 100 further includes a reflection module 140 configured to reflect laser light in a target wavelength mode among the laser light directed thereto toward the target module and to reflect laser light outside the target wavelength mode among the laser light directed thereto out of the target module, and the target module is the gain medium 130 or the electro-optic phase modulation module 110.

[0035] The reflecting module 140 may be used to reflect and filter out laser light directed thereto, such that laser light corresponding to the operating wavelength of the reflecting module (i.e., the targeted wavelength mode) may be reflected back to the targeted module, and laser light not corresponding to the operating wavelength of the reflecting module (i.e., outside the targeted wavelength mode) may be reflected and leaked out. In some embodiments, the reflecting module 140 includes a fully reflective mirror 41.

[0036] As shown in FIG. 2, in some embodiments, the reflector module 140 is configured as a fixed wavelength reflector module having an operating wavelength that cannot be modulated, whereby laser light is reflected to the target module.

[0037] As shown in FIG. 3, in some other embodiments of the present disclosure, the reflection module 140 is configured as an electro-optical reflection modulation module fabricated based on the electro-optical effect of an electro-optical material, and having an operating wavelength that can be modulated based on the electro-optical effect, in which laser light is reflected to the target module.

[0038] 1, in some embodiments, the optical modulation chip 100 includes an electro-optic phase modulation module 110 and a passband module 120, where the passband module 120 is an electro-optic passband modulation module. The electro-optic phase modulation module 110 is designed to have a strip waveguide 11.

[0039] 2, in some embodiments, the optical modulation chip 100 includes a sequentially arranged reflection module 140, a gain medium 130, an electro-optic phase modulation module 110, and a passband module 120, where the reflection module 140 is a fixed wavelength reflection module and the passband module 120 is an electro-optic passband modulation module. The electro-optic phase modulation module 110 is designed with a strip waveguide 11. In this embodiment, the reflection module 140 includes a total reflection mirror 41 and an optical power distribution element 42 configured to allow the input laser light to be split into two and then enter the total reflection mirror 41.

[0040] 3, in some embodiments, the optical modulation chip 100 includes a sequentially arranged reflection module 140, a gain medium 130, an electro-optic phase modulation module 110, and a passband module 120, where the reflection module 140 is an electro-optic reflection modulation module and the passband module 120 is a fixed passband module. The electro-optic phase modulation module 110 is designed to have a strip waveguide 11.

[0041] 4, in some embodiments, the optical modulation chip 100 includes a sequentially arranged reflection module 140, an electro-optic phase modulation module 110, a gain medium 130, and a passband module 120, where the reflection module 140 is an electro-optic reflection modulation module and the passband module 120 is a fixed passband module. The electro-optic phase modulation module 110 includes a strip waveguide 11.

[0042] 5, in some embodiments, the optical modulation chip 100 includes a sequentially arranged reflection module 140, an electro-optic phase modulation module 110, a gain medium 130, and a passband module 120, where the reflection module 140 is an electro-optic reflection modulation module and the passband module 120 is a fixed passband module. The electro-optic phase modulation module 110 includes a strip waveguide 11 and a ring resonator waveguide 12.

[0043] 5, the electro-optical reflection modulation module may include two directional couplers 44, so that the laser light of the target wavelength mode is emitted to the electro-optical phase modulation module 110, and the laser light of the other wavelength mode leaks out from the open port 43. A directional coupler is a microwave device widely used in microwave systems, which essentially performs power distribution of a microwave signal according to a specific ratio.

[0044] It should be noted that the structure of the optical modulation chip in the present disclosure is not limited to the structure of the above embodiment. In some embodiments of the present disclosure, for example, the optical modulation chip can also include a thermal phase modulation module, so that the wavelength tunable laser can have a wider modulation range, and the electro-optic phase modulation module cooperates with the thermal phase modulation module, thereby enabling the wavelength tunable laser to have a faster modulation speed.

[0045] An embodiment of the present disclosure also provides a tunable laser including the optical modulation chip 100 of any of the above embodiments. The tunable laser has a relatively fast modulation speed and better operating performance. Without being limited to a specific type of tunable laser, for example, the tunable laser may be a DFB laser or a DBR laser.

[0046] In this description, the orientations, positional relationships, or dimensions indicated by terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are those shown based on the accompanying drawings, and it should be understood that these terms are used for ease of description only and do not indicate or suggest that the referenced devices or elements must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of protection of the present disclosure.

[0047] Additionally, terms such as "first," "second," and "third" are for descriptive purposes only and should not be construed to indicate or suggest the relative importance or number of technical features being shown. Thus, features defined by "first," "second," and "third" can explicitly or implicitly include one or more features. In describing this disclosure, the term "plurality" means two or more, unless explicitly and specifically defined otherwise.

[0048] In this disclosure, unless expressly stated or defined otherwise, terms such as "attach," "connect," "connected," and "secure" should be interpreted broadly, for example, these terms may refer to a fixed connection, a detachable connection, or an integral connection, a mechanical connection or an electrical connection or communication, a direct connection or an indirect connection through an intermediate medium, or an internal communication between two elements or an interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in this disclosure according to the specific circumstances.

[0049] In this disclosure, unless expressly stated or defined otherwise, the phrase "above" or "below" a second feature can include cases where the first feature is in direct contact with the second feature, or cases where the first and second features are not in direct contact but are in contact via another feature between them. Furthermore, a first feature being "on," "above," or "on" a second feature can include cases where the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature can include cases where the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower level than the second feature.

[0050] This description provides many different implementation forms or examples that can be used to implement the present disclosure. It should be understood that these different implementation forms or examples are purely illustrative and are not intended to limit the scope of protection of the present disclosure in any way. Based on the disclosure of the description of the present disclosure, those skilled in the art may devise various modifications or replacements. All of these modifications or replacements shall fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure shall be governed by the scope of protection of the claims. [Explanation of symbols]

[0051] 100 Optical Modulation Chip 110 Electro-optic phase modulation module 120 Passband Module 130 Gain medium 140 Reflection Module 11 Strip waveguide 12 Ring resonator waveguide 13 Waveguide electrode 21 Passband electrode 41 Total reflection mirror 42 Optical Power Distribution Element 43 Open Port 44 Directional coupler

Claims

1. an electro-optic phase modulation module configured to modulate the wavelength of laser light input thereto based on the electro-optic effect and a target wavelength mode; a passband module configured to receive the laser light output by the electro-optic phase modulation module, reflect and then output at least a portion of the laser light input thereto in the target wavelength mode, and dissipate the laser light input thereto outside the target wavelength mode; a gain medium configured to optically amplify laser light input thereto; a reflection module having two directional couplers and an open port, wherein the reflection module is configured to reflect, among the laser light guided thereto, laser light in the target wavelength mode via the directional couplers to the target module, and to reflect, among the laser light guided thereto, laser light outside the target wavelength mode from the open port to outside the target module, wherein the target module is the electro-optic phase modulation module; the reflection module, the gain medium, the electro-optic phase modulation module, and the passband module are arranged in sequence; Light modulation chip.

2. the passband module is configured as a fixed passband module having an operating passband that cannot be modulated, or the passband module is configured as an electro-optic passband modulation module having an operating passband that can be modulated based on the electro-optic effect; The optical modulation chip according to claim 1 .

3. the passband module is configured as a passband grating module; The optical modulation chip according to claim 2 .

4. the passband module is configured as a distributed Bragg reflector passband grating module; The optical modulation chip according to claim 3 .

5. the reflector module is configured as a fixed wavelength reflector module having an operating wavelength that cannot be modulated, at which the laser light is reflected to the target module; or the reflecting module is configured as an electro-optical reflecting modulation module having an operating wavelength that can be modulated based on an electro-optical effect, in which the laser light is reflected to the target module; The optical modulation chip according to claim 1 .

6. The electro-optic phase modulation module comprises: a strip waveguide and a waveguide electrode for applying an electric field to said strip waveguide; and / or The optical modulation chip according to claim 1 , comprising: a ring resonator waveguide; and a waveguide electrode for applying an electric field to the ring resonator waveguide.

7. A wavelength tunable laser comprising the optical modulation chip according to any one of claims 1 to 5.

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