Broadband, high extinction ratio mid-infrared light intensity modulation devices, systems, and methods

Abstract

This invention discloses a wide-band, high extinction ratio mid-infrared light intensity modulation device, system, and method. The device includes: a dichroic mirror, a first beam splitter, a hollow-core fiber-based phase modulation component, an adjustable delay component, a first aperture, a second aperture, a beam combiner, and a filter. This invention couples mid-infrared signal light and near-infrared control light to the hollow-core fiber-based phase modulation component via the dichroic mirror and the first beam splitter to adjust the phase of the mid-infrared signal light. Simultaneously, the adjustable delay component adjusts the relative phase difference between the two signal lights output from the first beam splitter. Then, the first and second apertures adjust the output power of the two signal lights. Finally, the beam is combined by the beam combiner and filtered by the filter to obtain the mid-infrared signal modulated light. This invention provides a wide-band, high extinction ratio mid-infrared light intensity modulation device.

Description

Technical Field

[0001] This invention relates to the field of mid-infrared light intensity modulation technology, and in particular to a wide-band, high extinction ratio mid-infrared light intensity modulation device, system and method. Background Technology

[0002] The mid-infrared band primarily refers to the electromagnetic spectrum with wavelengths of 2-20 μm. Because this band has an atmospheric transparency window, and because the thermal radiation and molecular characteristic absorption peaks of objects are also located in this band, it is widely used in infrared thermal imaging observation, material composition analysis, and atmospheric environmental monitoring. Optical modulators are crucial devices in photonic links and sensing, enabling functions such as signal switching, routing, data encryption, and phase-sensitive detection. Existing mid-infrared optical modulators mainly employ waveguide integration, and their operating mechanisms typically fall into several categories: thermo-optic effect, electro-optic effect, free carrier dispersion effect, electro-absorption effect, and acousto-optic effect. Most mid-infrared waveguide-integrated modulators are electrically driven by external electronic units directly applied to the modulation unit, modulating the phase and intensity of the signal light by changing the crystal's refractive index through electrical signals.

[0003] However, due to the intrinsic absorption characteristics of crystal materials in the mid-infrared band, existing mid-infrared waveguide integrated modulators suffer from narrow operating bands and low modulation extinction ratios.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a wide-band, high-extinction-ratio mid-infrared light intensity modulation device, system and method to solve the problems of narrow operating band and low modulation extinction ratio of existing mid-infrared waveguide integrated modulators due to the intrinsic absorption characteristics of crystal materials in the mid-infrared band.

[0006] The technical solution of the present invention is as follows:

[0007] A wide-band, high extinction ratio mid-infrared light intensity modulation device, comprising: a dichroic mirror, a first beam splitter, a hollow fiber-based phase modulation component, an adjustable delay component, a first aperture, a second aperture, a beam combiner, and a filter.

[0008] The dichroic mirror is used to receive near-infrared control light and mid-infrared signal light and output them to the first beam splitter.

[0009] The first beam splitter is used to direct the near-infrared control light onto the hollow fiber-based phase modulation component, and to split the mid-infrared signal light into a first signal light and a second signal light, which are then output to the hollow fiber-based phase modulation component and the adjustable delay component, respectively.

[0010] The hollow fiber-based phase modulation component is used to adjust the phase of the first signal light and then output the phase-changed signal light to the first aperture.

[0011] The adjustable delay component is used to output the second signal light to the second aperture and adjust the relative phase difference between the first signal light and the second signal light;

[0012] The first aperture and the second aperture are used to adjust the output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component, respectively.

[0013] The beam combiner is used to combine the first signal light and the second signal light and output the combined beam light to the filter.

[0014] The filter is used to filter the combined light and output mid-infrared signal modulated light.

[0015] In a further embodiment of the present invention, the high extinction ratio mid-infrared light intensity modulation device further includes: a second beam splitter and a first detector;

[0016] The input end of the second beam splitter is connected to the output end of the filter, and the second beam splitter is used to split the mid-infrared modulated light into two outputs;

[0017] The first detector is connected to the first output terminal of the second beam splitter, and the first detector is used to convert the mid-infrared modulated light into an intensity signal and output it.

[0018] In a further embodiment of the present invention, the wide-band, high extinction ratio mid-infrared light intensity modulation device further includes: a second detector and a locking component; wherein,

[0019] The input end of the second detector is connected to the second output end of the second beam mirror. The second photodetector is used to convert the mid-infrared modulated light into an intensity signal and output it to the locking component.

[0020] The locking component is connected to the adjustable delay component, and the locking component is used to lock the position of the starting signal of the intensity modulation according to the intensity signal.

[0021] In a further embodiment of the present invention, the hollow-core fiber-based phase modulation assembly includes a hollow-core fiber, a focusing lens, a window, and a collimating lens; wherein,

[0022] The first output end of the first beam splitter enters the light input end of the hollow fiber through the focusing lens;

[0023] The light-emitting end of the hollow optical fiber enters the first aperture through the collimating lens, and is then output to the first input end of the beam combiner via the first aperture.

[0024] The focusing lens, the window, and the collimating lens constitute an air chamber assembly, and the hollow optical fiber is disposed in the air chamber assembly. Gas diffuses freely into the interior of the hollow optical fiber through the gap between the window and the hollow optical fiber.

[0025] In a further embodiment of the present invention, the hollow optical fiber is one of hollow photonic bandgap fiber, hollow anti-resonant negative curvature fiber, hollow Bragg fiber, or hollow glass tube.

[0026] In a further embodiment of the present invention, the hollow optical fiber is filled with an absorbing gas and a buffer gas, wherein the absorbing gas includes acetylene, methane and carbon dioxide, and the buffer gas includes nitrogen and argon.

[0027] In a further embodiment of the present invention, the near-infrared control light is a single-frequency near-infrared laser, and the wavelength of the single-frequency near-infrared laser is aligned with the absorption line of the gas molecules of the filling gas.

[0028] Based on the same inventive concept, the present invention also provides a wide-band, high extinction ratio mid-infrared light intensity modulation system, which includes a driving component and a wide-band, high extinction ratio mid-infrared light intensity modulation device as described above.

[0029] The driving component is connected to the dichroic mirror, and the driving component is used to generate near-infrared control light.

[0030] In a further embodiment of the present invention, the driving component includes: a tunable resonant laser, a power amplifier, and a power modulation unit;

[0031] The power modulation unit is connected to the tunable resonant laser and the power amplifier respectively. The power modulation unit is used to generate near-infrared control light according to the driving signal output by the power amplifier and the laser signal output by the tunable laser.

[0032] The wavelength of the tunable laser is aligned with the absorption line of the filling gas.

[0033] Based on the same inventive concept, the present invention also provides a method for modulating mid-infrared light intensity with a wide band and high extinction ratio applied to the aforementioned wide band and high extinction ratio mid-infrared light intensity modulation device, comprising:

[0034] The dichroic mirror directs the incoming near-infrared control light onto the hollow fiber-based phase modulation component, and splits the incoming mid-infrared signal light into a first signal light and a second signal light, which are then output to the hollow fiber-based phase modulation component and the adjustable delay component, respectively.

[0035] After adjusting the phase of the first signal light using a hollow fiber-based phase modulation component, the phase-changed signal light is output to the first aperture; wherein, the power or wavelength of the near-infrared control light is adjusted by a driving component to modulate the intensity of the first signal light;

[0036] The second signal light is output to the second aperture through an adjustable delay component, and the relative phase difference between the first signal light and the second signal light is adjusted.

[0037] The output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component are adjusted and output through the first and second apertures respectively;

[0038] The first signal light, after power adjustment, and the second signal light are combined by a beam combiner and then output to the filter.

[0039] The combined light is filtered by a filter to output mid-infrared signal modulated light.

[0040] A further provision of the present invention includes:

[0041] The mid-infrared signal modulated light is converted into an intensity signal output by a photodetector.

[0042] This invention provides a wide-band, high extinction ratio mid-infrared light intensity modulation device, system, and method. The device includes: a dichroic mirror, a first beam splitter, a hollow-core fiber-based phase modulation assembly, an adjustable delay assembly, a first aperture, a second aperture, a beam combiner, and a filter. The dichroic mirror is used to receive near-infrared control light and mid-infrared signal light and output them to the first beam splitter. The first beam splitter is used to incident the near-infrared control light onto the hollow-core fiber-based phase modulation assembly and to split the mid-infrared signal light into a first signal light and a second signal light, respectively outputting them to the hollow-core fiber-based phase modulation assembly and the adjustable delay assembly. The first optical element is used to adjust the phase of the first signal light and output the phase-changed signal light to the first aperture; the adjustable delay component is used to output the second signal light to the second aperture and adjust the relative phase difference between the first and second signal lights; the first and second apertures are used to adjust the output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component, respectively; the beam combiner is used to combine the first and second signal lights and output the combined beam light to the filter; the filter is used to filter the combined beam light and output mid-infrared signal modulated light. This invention couples mid-infrared signal light and near-infrared control light to a hollow-core fiber-based phase modulation component via a dichroic mirror to adjust the phase of the mid-infrared signal light. Simultaneously, an adjustable delay component adjusts the relative phase difference between the two signal lights output from a first beam splitter. Then, a first and second aperture adjust the output power of the two signal lights. Finally, a beam combiner combines the two beams, filters them, and outputs the mid-infrared modulated light. This invention uses a hollow-core fiber-based phase modulation component as a carrier. Because hollow-core fiber has wide-band transmission characteristics and contains gas-filled material with intrinsically narrow absorption lines, it can achieve wide-band intensity modulation from near-infrared to mid-infrared signal light. Furthermore, by placing apertures at the output ends of the hollow-core fiber-based phase modulation component and the adjustable delay component, and adjusting the power output of the two output light signals using these apertures, a high modulation extinction ratio is achieved, resulting in a mid-infrared light intensity modulation device with a wide operating band and a high extinction ratio. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0044] Figure 1This is a schematic diagram of the principle of the mid-infrared light intensity modulation system with wide band and high extinction ratio in this invention.

[0045] Figure 2 This is a schematic diagram of the cross-section of the hollow-core optical fiber in this invention.

[0046] Figure 3 This is a waveform relationship diagram of near-infrared control light and mid-infrared signal light at a modulation frequency of 20Hz for the wide-band, high extinction ratio mid-infrared light intensity modulation system of this invention.

[0047] Figure 4 This is a schematic flowchart of the mid-infrared light intensity modulation method with wide band and high extinction ratio in this invention.

[0048] The following are the labels in the attached diagram: 1. Driving component; 2. Dichroic mirror; 3. First beam splitter; 4. Hollow-core fiber-based phase modulation component; 41. Hollow-core fiber; 5. Adjustable delay component; 6. First aperture; 7. Second aperture; 8. Beam combiner; 9. Filter; 10. Second beam splitter; 11. First detector; 12. Second detector; 13. Locking component. Detailed Implementation

[0049] This invention provides a wide-band, high extinction ratio mid-infrared light intensity modulation device, system, and method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0050] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0051] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0052] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0053] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0054] The inventors discovered that most mid-infrared waveguide integrated modulators are electrically driven by external electronic units directly applied to the modulation unit. The phase and intensity of the signal light are modulated by changing the crystal's refractive index through electrical signals. While mid-infrared waveguide integrated modulators offer advantages such as small size, existing models suffer from problems due to the intrinsic absorption characteristics of crystal materials in the mid-infrared band. These problems include narrow operating bands, low modulation extinction ratios, high manufacturing costs, significant fabrication difficulties, substantial absorption and scattering losses, and poor resistance to electromagnetic interference.

[0055] To address the aforementioned technical problems, this invention provides a wide-band, high extinction ratio mid-infrared light intensity modulation device, system, and method. The method involves coupling mid-infrared signal light and near-infrared control light to a hollow-core fiber-based phase modulation assembly via a dichroic mirror to adjust the phase of the mid-infrared signal light. Simultaneously, an adjustable delay component adjusts the relative phase difference between the two signal lights output from a first beam splitter. Subsequently, a first and second aperture are used to adjust the output power of the two signal lights. Finally, a beam combiner is used to combine the two beams, which are then filtered to obtain the mid-infrared signal modulated light. This invention uses a hollow-core fiber-based phase modulation assembly as the carrier. Because hollow-core fiber has wide-band transmission characteristics and contains gas-filled material with intrinsically narrow absorption lines, it can achieve wide-band intensity modulation from near-infrared signal light to mid-infrared signal light. Furthermore, this invention achieves a high modulation extinction ratio by setting an aperture at the output end of the hollow-core fiber-based phase modulation component and the adjustable delay component, thereby adjusting the power output of the two output optical signals. This results in a mid-infrared light intensity modulation device with a wide operating wavelength and a high extinction ratio. Moreover, this invention has a simple fabrication process, low manufacturing cost, low absorption and scattering losses, and is less susceptible to electromagnetic interference.

[0056] Please also refer to Figures 1 to 3 The present invention provides a preferred embodiment of a mid-infrared light intensity modulation system with a wide band and high extinction ratio.

[0057] like Figure 1 As shown, the present invention provides a wide-band, high-extinction-ratio mid-infrared light intensity modulation system, which includes a driving component 1 and a wide-band, high-extinction-ratio mid-infrared light intensity modulation device. The driving component 1 is connected to the wide-band, high-extinction-ratio mid-infrared light intensity modulation device. The driving component 1 can generate near-infrared control light to modulate the mid-infrared signal light and output it to the wide-band, high-extinction-ratio mid-infrared light intensity modulation device. The intensity of the mid-infrared signal light incident on the wide-band, high-extinction-ratio mid-infrared light intensity modulation device can be modulated by adjusting the power or wavelength of the near-infrared control light.

[0058] In some embodiments, the wide-band, high extinction ratio mid-infrared light intensity modulation device includes: a dichroic mirror 2, a first beam splitter 3, a hollow-core fiber-based phase modulation component 4, an adjustable delay component 5, a first aperture 6, a second aperture 7, a beam combiner 8, and a filter 9. The dichroic mirror 2 is used to receive the near-infrared control light and the mid-infrared signal light and output them to the first beam splitter 3; the first beam splitter 3 is used to incident the near-infrared control light onto the hollow-core fiber-based phase modulation component 4, and to split the mid-infrared signal light into a first signal light and a second signal light, respectively outputting them to the hollow-core fiber-based phase modulation component 4 and the adjustable delay component 5; the hollow-core fiber-based phase modulation component 4 is used to adjust the phase of the first signal light and output the phase-changed signal light to the first aperture 6; the adjustable delay... Component 5 is used to output the second signal light to the second aperture 7 and adjust the relative phase difference between the first signal light and the second signal light; the first aperture 6 and the second aperture 7 are used to adjust the output power of the first signal light output by the hollow fiber-based phase modulation component 4 and the second signal light output by the adjustable delay component 5, respectively; the beam combiner 8 is used to combine the first signal light and the second signal light and output the combined light to the filter 9; the filter 9 is used to filter the combined light and output mid-infrared signal modulated light.

[0059] Specifically, the first input terminal of the dichroic mirror 2 is connected to the output terminal of the driving component 1, the second input terminal of the dichroic mirror 2 is connected to mid-infrared signal light, and the output terminal of the dichroic mirror 2 is connected to the input terminal of the first beam splitter 3. The first output terminal of the first beam splitter 3 is connected to the hollow-core fiber-based phase modulation component 4, and the second output terminal of the first beam splitter 3 is connected to the adjustable delay component 5. The output terminals of the hollow-core fiber-based phase modulation component 4 and the adjustable delay component 5 are respectively connected to the first aperture 6 and the second aperture 7. The first input terminal of the beam combiner 8 is connected to the first aperture 6, the second input terminal of the beam combiner 8 is connected to the second aperture 7, and the output terminal of the beam combiner 8 is connected to the input terminal of the filter 9. The dichroic mirror 2, the first beam splitter 3, the hollow fiber-based phase modulation component 4, the adjustable delay component 5, the first aperture 6, the second aperture 7, the beam combiner 8, and the filter 9 constitute a Mach-Zehnder interferometer. The hollow fiber-based phase modulation component 4 serves as the transmission carrier and as the phase arm of the Mach-Zehnder interferometer, while the adjustable delay component 5 serves as the reference arm of the Mach-Zehnder interferometer.

[0060] This invention couples mid-infrared signal light and near-infrared control light to a hollow-core fiber-based phase modulation component 4 via a dichroic mirror 2 to adjust the phase of the mid-infrared signal light. Simultaneously, an adjustable delay component 5 adjusts the relative phase difference between the two signal lights output from the first beam splitter 3 to avoid the influence of environmental disturbances on the test results. Subsequently, the output power of the two signal lights is adjusted by the first aperture 6 and the second aperture 7. After beam combining by a beam combiner 8, the beams are filtered by a filter 9 to remove the unabsorbed near-infrared control light (most of the near-infrared control light is absorbed by gas molecules, and a small portion enters the filter along with the mid-infrared signal light). The output light through the filter 9 is only the mid-infrared signal modulated light. The intensity modulation of the mid-infrared signal light can be achieved by adjusting the power or wavelength of the near-infrared control light by the driving component 1.

[0061] This invention uses a hollow-core fiber-based phase modulation component 4 as a carrier. Because hollow-core fiber possesses wide-band transmission characteristics and contains gas-filled material with intrinsically narrow absorption lines, it can achieve ultra-wideband intensity modulation from near-infrared to mid-infrared signal light. Furthermore, by placing apertures at the output ends of the hollow-core fiber-based phase modulation component 4 and the adjustable delay component 5, and adjusting the power output of the two output optical signals using these apertures, a high modulation extinction ratio is achieved, resulting in a mid-infrared light intensity modulation device with a wide operating band and high extinction ratio. Moreover, this invention has a simple fabrication process, low manufacturing cost, low absorption and scattering losses, and is less susceptible to electromagnetic interference.

[0062] Please see Figure 1 and Figure 2 In a further embodiment of one example, the hollow fiber-based phase modulation assembly 4 includes a hollow fiber 41, a focusing lens, a window, and a collimating lens. The first output end of the first beam splitter 3 enters the input end of the hollow fiber 41 through the focusing lens; the output end of the hollow fiber 41 enters the first aperture 6 through the collimating lens and is output to the first input end of the beam combiner 8. The focusing lens, the window, and the collimating lens constitute a gas chamber assembly, and the hollow fiber 41 is disposed within the gas chamber assembly. Gas diffuses freely into the interior of the hollow fiber through the gap between the window and the hollow fiber.

[0063] Specifically, the hollow-core optical fiber 41 is a hollow-core microstructure optical fiber with a sealed inner cavity filled with an absorbing gas. The hollow-core optical fiber 41 is placed in a gas chamber assembly with a window. The gas diffuses freely into the hollow-core optical fiber through the gap between the window and the hollow-core optical fiber, and then the entire gas chamber is further sealed with adhesive. The hollow-core optical fiber serves as a transmission carrier, and a photothermal effect is induced by the interaction between the near-infrared control light and gas molecules. When the mid-infrared light signal and the near-infrared control light are simultaneously coupled into the gas-filled hollow-core optical fiber through the dichroic mirror 2, the near-infrared control light in the hollow-core optical fiber region interacts with the gas molecules and releases heat. This changes the refractive index of the gas and the phase of the mid-infrared signal light, thereby causing an intensity change in the Mach-Zehnder interferometer. The intensity of the mid-infrared signal light can be modulated by adjusting the power or wavelength of the near-infrared control light.

[0064] It should be noted that, in addition to using collimating lens coupling, the coupling method between the idle optical fiber and the near-infrared control light and the mid-infrared light signal can also be other methods, such as optical fiber coupling.

[0065] In some embodiments, the hollow fiber may be one of hollow photonic bandgap fiber, hollow anti-resonant negative curvature fiber, hollow Bragg fiber, or hollow glass tube. For example, in one implementation, the hollow fiber may be a hollow photonic bandgap fiber.

[0066] In some embodiments, the hollow optical fiber is filled with an absorbing gas and a buffer gas, wherein the absorbing gas includes acetylene, methane and carbon dioxide, and the buffer gas includes nitrogen and argon.

[0067] Specifically, the hollow optical fiber is filled with an absorbing gas and a buffer gas. In the hollow region, the near-infrared control light interacts with the gas molecules, causing a photothermal effect and realizing a change in the refractive index and phase within the hollow optical fiber. In one implementation, the absorbing gas can be acetylene, and the buffer gas can be nitrogen.

[0068] In some embodiments, the near-infrared control light is a single-frequency near-infrared laser, and the wavelength of the single-frequency near-infrared laser is aligned with the absorption line of the gas molecules in the filling gas.

[0069] Please see Figure 1In a further embodiment of one example, the high extinction ratio mid-infrared light intensity modulation device further includes: a second beam splitter 10 and a first detector 11. The input end of the second beam splitter 10 is connected to the output end of the filter 9, and the second beam splitter 10 is used to split the mid-infrared modulated light into two outputs. The first detector 11 is connected to the first output end of the second beam splitter 10, and the first detector 11 is used to convert the mid-infrared modulated light into an intensity signal and output it.

[0070] Specifically, the mid-infrared modulated light reaches the first detector 11 after passing through the second beam splitter 10. After photoelectric conversion by the first detector 11, the mid-infrared modulated light is converted into an electrical signal (i.e., an intensity signal) and output.

[0071] Please continue reading. Figure 1 In a further embodiment of one example, the wide-band, high extinction ratio mid-infrared light intensity modulation device further includes: a second detector 12 and a locking component 13. The input end of the second detector is connected to the second output end of the second beam mirror, and the second detector 12 is used to convert the mid-infrared modulated light into an intensity signal and output it to the locking component 13; the locking component 13 is connected to the adjustable delay component 5, and the locking component 13 is used to lock the starting signal position of the intensity modulation according to the intensity signal.

[0072] Specifically, the second detector 12 is connected to the second output terminal of the second beam splitter 10, converts the mid-infrared light signal into an electrical signal (intensity signal) and outputs it to the locking component 13. The output terminal of the locking component 13 is connected to the adjustable delay component 5 to lock the position of the intensity modulation start signal.

[0073] Please see Figure 1 In a further embodiment of one example, the driving component 1 includes: a tunable resonant laser, a power amplifier, and a power modulation unit. The power modulation unit is connected to both the tunable resonant laser and the power amplifier, and is used to generate near-infrared control light based on a driving signal output from the power amplifier and a laser signal output from the tunable laser; wherein the wavelength of the tunable laser is aligned with the absorption line of the filling gas.

[0074] Specifically, the wavelength of the tunable resonant laser is aligned with the absorption line of the filling gas. For example, when the filling gas is acetylene, the tunable resonant laser is aligned with the P(9) absorption line of acetylene. The power of the near-infrared control light in the hollow fiber is modulated by adjusting the driving signal applied to the power modulation unit, thereby modulating the intensity of the mid-infrared signal light. Alternatively, the power of the near-infrared control light can be kept constant, and the wavelength of the laser signal can be adjusted to modulate the wavelength of the near-infrared control light in the hollow fiber, thereby modulating the intensity of the mid-infrared signal light.

[0075] Please see Figure 3 When the near-infrared control light is modulated with a square wave at a repetition frequency of 20 Hz and a duty cycle of 50:50, the mid-infrared signal light exhibits the same trend. Specifically, when the near-infrared control light is 0, the output of the mid-infrared signal light is almost zero, corresponding to the "off" state; when the near-infrared control light is at its maximum value, the output of the mid-infrared signal light is at its maximum value, corresponding to the "on" state. For the square-wave modulated near-infrared control light, the output amplitude of the mid-infrared signal light periodically varies between zero and its maximum value, achieving a modulation extinction ratio of at least 25 dB.

[0076] Please see Figure 4 In some embodiments, the present invention also provides a method for modulating mid-infrared light intensity with a wide band and high extinction ratio applied to the aforementioned wide band and high extinction ratio mid-infrared light intensity modulation system, comprising the steps of:

[0077] S100 and the dichroic mirror direct the incoming near-infrared control light to the hollow-core fiber-based phase modulation component, and split the incoming mid-infrared signal light into a first signal light and a second signal light, which are then output to the hollow-core fiber-based phase modulation component and the adjustable delay component, respectively; as described in an embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, which will not be repeated here.

[0078] S200: After adjusting the phase of the first signal light using a hollow fiber-based phase modulation component, the phase-changed signal light is output to the first aperture; wherein, the power or wavelength of the near-infrared control light is adjusted by a driving component to modulate the intensity of the first signal light; specifically as described in an embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, which will not be repeated here.

[0079] S300, The second signal light is output to the second aperture through the adjustable delay component, and the relative phase difference between the first signal light and the second signal light is adjusted; as described in the embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, which will not be repeated here.

[0080] S400, the output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component are adjusted and output through the first aperture and the second aperture respectively; specifically as described in an embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, which will not be repeated here.

[0081] S500: The first signal light with power adjustment and the second signal light are combined by a beam combiner and then output to the filter; as described in an embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, which will not be repeated here.

[0082] S600: After filtering the combined light through a filter, the output is a mid-infrared signal modulated light. This is specifically described in an embodiment of a wide-band, high extinction ratio mid-infrared light intensity modulation system, and will not be repeated here.

[0083] In summary, the mid-infrared light intensity modulation device, system, and method with a wide wavelength range and high extinction ratio provided by this invention have the following beneficial effects:

[0084] Using a hollow fiber-based phase modulation component as a carrier, the hollow fiber has wide-band transmission characteristics and contains gas-filled material with intrinsic narrow absorption lines, thus enabling wide-band intensity modulation from near-infrared signal light to mid-infrared signal light. By setting an aperture at the output end of the hollow fiber-based phase modulation component and the adjustable delay component, the power output of the two output optical signals can be adjusted through the aperture, achieving a high modulation extinction ratio. In this way, a mid-infrared light intensity modulation device with a wide operating band and a high extinction ratio can be obtained.

[0085] The preparation process is simple, the production cost is low, the absorption and scattering losses are small, and it is not easily affected by electromagnetic interference.

[0086] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A mid-infrared light intensity modulation device with a wide wavelength range and high extinction ratio, characterized in that, include: Dichroic mirror, first beam splitter, hollow fiber-based phase modulation assembly, adjustable delay assembly, first aperture, second aperture, beam combiner and filter; The dichroic mirror is used to receive near-infrared control light and mid-infrared signal light and output them to the first beam splitter. The first beam splitter is used to direct the near-infrared control light onto the hollow fiber-based phase modulation assembly, and to split the mid-infrared signal light into a first signal light and a second signal light, which are then output to the hollow fiber-based phase modulation assembly and the adjustable delay assembly, respectively. The hollow fiber-based phase modulation component is used to adjust the phase of the first signal light and then output the phase-changed signal light to the first aperture. The adjustable delay component is used to output the second signal light to the second aperture and adjust the relative phase difference between the first signal light and the second signal light; The first aperture and the second aperture are used to adjust the output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component, respectively. The beam combiner is used to combine the first signal light and the second signal light and output the combined beam light to the filter. The filter is used to filter the combined light and output mid-infrared signal modulated light.

2. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 1, characterized in that, Also includes: The second beam splitter and the first detector; The input end of the second beam splitter is connected to the output end of the filter, and the second beam splitter is used to split the mid-infrared modulated light into two outputs; The first detector is connected to the first output terminal of the second beam splitter, and the first detector is used to convert the mid-infrared modulated light into an intensity signal and output it.

3. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 2, characterized in that, Also includes: The second detector and locking assembly; wherein... The input terminal of the second detector is connected to the second output terminal of the second beam splitter. The second detector is used to convert the mid-infrared modulated light into an intensity signal and output it to the locking component. The locking component is connected to the adjustable delay component, and the locking component is used to lock the position of the starting signal of the intensity modulation according to the intensity signal.

4. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 1, characterized in that, The hollow-core fiber-based phase modulation assembly includes: a hollow-core fiber, a focusing lens, a window, and a collimating lens; wherein... The first output end of the first beam splitter enters the light input end of the hollow fiber through the focusing lens; The light-emitting end of the hollow optical fiber enters the first aperture through the collimating lens, and is then output to the first input end of the beam combiner via the first aperture. The focusing lens, the window, and the collimating lens constitute an air chamber assembly, and the hollow optical fiber is disposed in the air chamber assembly. Gas diffuses freely into the interior of the hollow optical fiber through the gap between the window and the hollow optical fiber.

5. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 4, characterized in that, The hollow optical fiber is one of the following: hollow photonic bandgap fiber, hollow anti-resonant negative curvature fiber, hollow Bragg fiber, or hollow glass tube.

6. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 5, characterized in that, The hollow optical fiber is filled with an absorbing gas and a buffer gas, wherein the absorbing gas includes acetylene, methane and carbon dioxide, and the buffer gas includes nitrogen and argon.

7. The wide-band, high extinction ratio mid-infrared light intensity modulation device according to claim 6, characterized in that, The near-infrared control light is a single-frequency near-infrared laser, and the wavelength of the single-frequency near-infrared laser is aligned with the absorption line of the gas molecules in the filling gas.

8. A mid-infrared light intensity modulation system with a wide wavelength range and high extinction ratio, characterized in that, Includes driving components and a wide-band, high extinction ratio mid-infrared light intensity modulation device as described in any one of claims 1-7; The driving component is connected to the dichroic mirror and is used to generate near-infrared control light.

9. The wide-band, high extinction ratio mid-infrared light intensity modulation system according to claim 8, characterized in that, The driving components include: a wavelength-tunable resonant laser, a power amplifier, and a power modulation unit; The power modulation unit is connected to the wavelength-tunable resonant laser and the power amplifier respectively. The power modulation unit is used to generate near-infrared control light according to the driving signal output by the power amplifier and the laser signal output by the wavelength-tunable resonant laser. The wavelength of the wavelength-tunable resonant laser is aligned with the absorption line of the filling gas.

10. A method for modulating mid-infrared light intensity with a wide band and high extinction ratio applied to the mid-infrared light intensity modulation system of claim 8 or 9, characterized in that, include: The dichroic mirror directs the incoming near-infrared control light onto the hollow fiber-based phase modulation component, and splits the incoming mid-infrared signal light into a first signal light and a second signal light, which are then output to the hollow fiber-based phase modulation component and the adjustable delay component, respectively. After adjusting the phase of the first signal light using a hollow fiber-based phase modulation component, the phase-changed signal light is output to the first aperture; wherein, the power or wavelength of the near-infrared control light is adjusted by a driving component to modulate the intensity of the first signal light; The second signal light is output to the second aperture through an adjustable delay component, and the relative phase difference between the first signal light and the second signal light is adjusted. The output power of the first signal light output by the hollow fiber-based phase modulation component and the second signal light output by the adjustable delay component are adjusted and output through the first and second apertures respectively; The first signal light, after power adjustment, and the second signal light are combined by a beam combiner and then output to the filter. The combined light is filtered by a filter to output mid-infrared signal modulated light.

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