Pulse modulation circuit of ultra-wideband super-continuous fiber laser
The three-stage filtering architecture solves the problems of power supply ripple coupling and phase noise enhancement in ultra-wideband supercontinuous fiber lasers, achieving stable power supply with low phase noise and ensuring the timing accuracy of spectral laser pulses.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- UNIV OF ELECTRONICS SCI & TECH OF CHINA
- Filing Date
- 2025-09-22
- Publication Date
- 2026-04-17
AI Technical Summary
In the pulse modulation circuit of ultrawideband supercontinuous fiber lasers, the power supply ripple coupling and the insufficient performance of the LDO filter network lead to an increase in the phase noise floor of the clock circuit.
It adopts a three-stage filtering architecture, including an input filtering module, a low-dropout linear regulator module, and a π-type filter module. Through components such as power inductors, ceramic capacitors, low-dropout linear regulators, and high-frequency ferrite beads, it achieves high-frequency ripple filtering and noise absorption, providing a stable power supply with low phase noise.
An ultra-stable power supply with a phase noise floor of less than -152dBc/Hz@1kHz was achieved, ensuring the timing accuracy of supercontinuum laser pulses.
Smart Images
Figure CN224138892U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ultra-wideband supercontinuous fiber laser technology, and in particular to a pulse modulation circuit for an ultra-wideband supercontinuous fiber laser. Background Technology
[0002] Ultrawideband supercontinuum fiber lasers are a novel type of light source based on the nonlinear effects of optical fibers. They can convert narrowband seed light into continuous light covering an ultrawide spectral range. Relying on highly nonlinear optical fibers and other devices, they achieve maximum spectral broadening through self-phase modulation and four-wave mixing. They feature stable output power, good coherence, and wide spectral coverage, making them widely used in optical coherence tomography, spectroscopy, remote sensing, and optical communication, providing crucial light source support for multidisciplinary research and technological development.
[0003] In the actual operation of the pulse modulation circuit of ultra-wideband supercontinuous fiber laser, insufficient power supply ripple coupling and LDO filter network efficiency, such as excessively high output capacitor ESR or lack of π-type filter, will directly raise the phase noise floor of the clock circuit.
[0004] Therefore, a pulse modulation circuit for an ultra-wideband supercontinuous fiber laser is proposed to solve or alleviate the above problems. Utility Model Content
[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a pulse modulation circuit for an ultra-wideband supercontinuous fiber laser.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A pulse modulation circuit for an ultrawideband supercontinuum fiber laser includes an input filtering module, a low-dropout linear regulator module, a π-type filter module, a clock power supply distribution module, and a grounding system module.
[0008] The input terminal of the input filter module is used to connect to an external power supply. The input terminal of the low-dropout linear regulator module is connected to the output terminal of the input filter module. The input terminal of the π-type filter module is connected to the output terminal of the low-dropout linear regulator module. The input terminal of the clock power supply distribution module is connected to the output terminal of the π-type filter module. The grounding system module includes mutually isolated analog ground planes and digital ground planes, which are electrically interconnected through a single physical connection point. All grounding terminals of the input filter module, the low-dropout linear regulator module, and the π-type filter module are connected to the analog ground plane.
[0009] Preferably, the input filtering module includes a power inductor, a first ceramic capacitor, and a second ceramic capacitor. The first current terminal of the power inductor is used to connect to an external power supply. The positive terminal of the first ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the first ceramic capacitor is connected to an analog ground plane. The positive terminal of the second ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the second ceramic capacitor is connected to an analog ground plane. The second current terminal of the power inductor is set as the output terminal of the input filtering module.
[0010] Preferably, the low dropout linear regulator module includes an LDO regulator, a current-limiting resistor, a third ceramic capacitor, and a fourth ceramic capacitor. The voltage input terminal of the LDO regulator is connected to the output terminal of the input filter module. The enable control terminal of the LDO regulator is used to connect to an external enable signal. The ground terminal of the LDO regulator is connected to an analog ground plane. The first conductive terminal of the current-limiting resistor is connected to the voltage output terminal of the LDO regulator. The positive terminals of the third and fourth ceramic capacitors are both connected to the second conductive terminal of the current-limiting resistor. The negative terminals of the third and fourth ceramic capacitors are both connected to an analog ground plane. The second conductive terminal of the current-limiting resistor is set as the output terminal of the low dropout linear regulator module.
[0011] Preferably, the π-type filter module includes a high-frequency ferrite bead, a fifth ceramic capacitor, a sixth ceramic capacitor, and a seventh ceramic capacitor. The first signal terminal of the high-frequency ferrite bead is connected to the output terminal of the low-dropout linear regulator module. The positive terminal of the fifth ceramic capacitor is connected to the first signal terminal of the high-frequency ferrite bead. The positive terminals of the sixth and seventh ceramic capacitors are both connected to the second signal terminals of the high-frequency ferrite bead. The negative terminals of the fifth, sixth, and seventh ceramic capacitors are all connected to the analog ground plane. The second signal terminal of the high-frequency ferrite bead is set as the output terminal of the π-type filter module.
[0012] Preferably, the clock power supply distribution module includes a zero-ohm resistor, an HMC7044LP10GE clock generator, a first decoupling capacitor, and a second decoupling capacitor. The first conductive terminal of the zero-ohm resistor is connected to the output terminal of the π-type filter module. The analog power supply terminal of the HMC7044LP10GE clock generator is connected to the second conductive terminal of the zero-ohm resistor. The digital power supply terminal of the HMC7044LP10GE clock generator is connected to the second conductive terminal of the zero-value impedance element. The positive terminal of the first decoupling capacitor is connected to the analog power supply terminal of the HMC7044LP10GE clock generator, and the negative terminal of the first decoupling capacitor is connected to the analog ground terminal of the HMC7044LP10GE clock generator. The positive terminal of the second decoupling capacitor is connected to the digital power supply terminal of the HMC7044LP10GE clock generator, and the negative terminal of the second decoupling capacitor is connected to the digital ground terminal of the HMC7044LP10GE clock generator. The digital ground terminal of the HMC7044LP10GE clock generator is connected to the digital ground plane.
[0013] This utility model has the following beneficial effects:
[0014] This invention employs a three-stage sequential filtering architecture to filter out high-frequency ripple, suppress voltage ripple depth, and absorb residual noise from the power output. Ultimately, it provides the clock circuit with an ultra-stable power supply with a phase noise floor of less than -152dBc / Hz@1kHz offset, ensuring the timing accuracy of supercontinuum laser pulses. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a structural block diagram of the present invention.
[0017] In the diagram: 1. Input filter module; 2. Low dropout linear regulator module; 3. π-type filter module; 4. Clock power supply distribution module; 5. Grounding system module. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0021] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0022] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0023] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] A pulse modulation circuit for an ultrawideband supercontinuum fiber laser, such as Figure 1As shown, the system includes an input filter module 1, a low-dropout linear regulator module 2, a π-type filter module 3, a clock power distribution module 4, and a grounding system module 5. The input terminal of the input filter module 1 is used to connect to an external power supply. The input terminal of the low-dropout linear regulator module 2 is connected to the output terminal of the input filter module 1. The input terminal of the π-type filter module 3 is connected to the output terminal of the low-dropout linear regulator module 2. The input terminal of the clock power distribution module 4 is connected to the output terminal of the π-type filter module 3. The grounding system module 5 includes an isolated analog ground plane and a digital ground plane, which are electrically interconnected through a single physical connection point. All grounding terminals of the input filter module 1, the low-dropout linear regulator module 2, and the π-type filter module 3 are connected to the analog ground plane.
[0025] The input filtering module 1 includes a power inductor, a first ceramic capacitor, and a second ceramic capacitor. The first current terminal of the power inductor is used to connect to an external power supply. The positive terminal of the first ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the first ceramic capacitor is connected to the analog ground plane. The positive terminal of the second ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the second ceramic capacitor is connected to the analog ground plane. The second current terminal of the power inductor is set as the output terminal of the input filtering module 1.
[0026] The low dropout linear regulator module 2 includes an LDO regulator, a current-limiting resistor, a third ceramic capacitor, and a fourth ceramic capacitor. The voltage input terminal of the LDO regulator is connected to the output terminal of the input filter module 1. The enable control terminal of the LDO regulator is used to connect to an external enable signal. The ground terminal of the LDO regulator is connected to the analog ground plane. The first conductive terminal of the current-limiting resistor is connected to the voltage output terminal of the LDO regulator. The positive terminals of the third and fourth ceramic capacitors are both connected to the second conductive terminal of the current-limiting resistor. The negative terminals of the third and fourth ceramic capacitors are both connected to the analog ground plane. The second conductive terminal of the current-limiting resistor is set as the output terminal of the low dropout linear regulator module 2. The LDO regulator is model ADP7104.
[0027] The π-type filter module 3 includes a high-frequency ferrite bead, a fifth ceramic capacitor, a sixth ceramic capacitor, and a seventh ceramic capacitor. The first signal terminal of the high-frequency ferrite bead is connected to the output terminal of the low-dropout linear regulator module 2. The positive terminal of the fifth ceramic capacitor is connected to the first signal terminal of the high-frequency ferrite bead. The positive terminals of the sixth and seventh ceramic capacitors are both connected to the second signal terminal of the high-frequency ferrite bead. The negative terminals of the fifth, sixth, and seventh ceramic capacitors are all connected to the analog ground plane. The second signal terminal of the high-frequency ferrite bead is set as the output terminal of the π-type filter module 3.
[0028] The clock power supply distribution module 4 includes a zero-ohm resistor, an HMC7044LP10GE clock generator, a first decoupling capacitor, and a second decoupling capacitor. The first conductive terminal of the zero-ohm resistor is connected to the output terminal of the π-type filter module 3. The analog power supply terminal of the HMC7044LP10GE clock generator is connected to the second conductive terminal of the zero-ohm resistor. The digital power supply terminal of the HMC7044LP10GE clock generator is connected to the second conductive terminal of the zero-value impedance element. The positive terminal of the first decoupling capacitor is connected to the analog power supply terminal of the HMC7044LP10GE clock generator, and the negative terminal of the first decoupling capacitor is connected to the analog ground terminal of the HMC7044LP10GE clock generator. The positive terminal of the second decoupling capacitor is connected to the digital power supply terminal of the HMC7044LP10GE clock generator, and the negative terminal of the second decoupling capacitor is connected to the digital ground terminal of the HMC7044LP10GE clock generator. The digital ground terminal of the HMC7044LP10GE clock generator is connected to the digital ground plane.
[0029] The pulse modulation circuit of this ultrawideband supercontinuum fiber laser solves the problems of power supply ripple coupling and phase noise floor rise through a three-stage synergistic filter.
[0030] Specifically,
[0031] When the pulsating DC power output from the power supply enters the input filter module 1, the power inductor and the first and second ceramic capacitors connected in parallel form an LC network, which first filters out MHz-level high-frequency ripple. The equivalent series resistance of the ceramic capacitor is strictly controlled below 3mΩ, thus avoiding the degradation of filtering performance caused by excessively high ESR of the output capacitor in traditional solutions from the source.
[0032] After the pre-processed current input low dropout linear regulator module 2, the ADP7104's LDO regulator achieves deep voltage regulation with an ultra-high power rejection ratio of 78dB@100kHz. The current-limiting resistor connected in series at its voltage output terminal, along with the third and fourth ceramic capacitors connected in parallel, form an adaptive RC network that dynamically compensates for the load transient response and suppresses residual intermediate frequency ripple to the μV level.
[0033] The π-type filter module 3 uses a 600Ω@100MHz high-frequency ferrite bead connected in series with the fifth, sixth, and seventh ceramic capacitors. The first signal terminal of the high-frequency ferrite bead is connected to the fifth ceramic capacitor to absorb the broadband noise remaining at the output of the LDO regulator. The second signal terminal of the high-frequency ferrite bead is connected in parallel with the sixth and seventh ceramic capacitors to form a composite absorption network. This solves the RF noise coupling defect when the π-type filter is missing. Through the frequency-varying impedance characteristics of the high-frequency ferrite bead and the full-band coverage of the capacitor bank, an additional ripple attenuation of 40dB@100kHz is achieved.
[0034] The purified DC power is supplied to the HMC7044LP10GE clock generator via a dual-path supply through a zero-ohm resistance test point. The analog power supply channel is connected to the HMC7044LP10GE clock generator through an ultra-short ≤1mm trace and equipped with a first decoupling capacitor. The digital power supply channel is connected with equal constraints and equipped with a second decoupling capacitor. The dual independent power supply eliminates crosstalk between digital noise and analog circuits.
[0035] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A pulse modulation circuit for an ultra-broadband supercontinuum fiber laser, characterized in that, It includes an input filtering module (1), a low dropout linear regulator module (2), a π-type filter module (3), a clock power supply distribution module (4), and a grounding system module (5); The input terminal of the input filter module (1) is used to connect to an external power supply. The input terminal of the low dropout linear regulator module (2) is connected to the output terminal of the input filter module (1). The input terminal of the π-type filter module (3) is connected to the output terminal of the low dropout linear regulator module (2). The input terminal of the clock power supply distribution module (4) is connected to the output terminal of the π-type filter module (3). The grounding system module (5) includes an isolated analog ground plane and a digital ground plane, which are electrically interconnected through a single physical connection point. All grounding terminals of the input filter module (1), the low dropout linear regulator module (2), and the π-type filter module (3) are connected to the analog ground plane.
2. The pulse modulation circuit for an ultra-wideband supercontinuum fiber laser according to claim 1, characterized in that, The input filtering module (1) includes a power inductor, a first ceramic capacitor, and a second ceramic capacitor. The first current terminal of the power inductor is used to connect to an external power supply. The positive terminal of the first ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the first ceramic capacitor is connected to the simulated ground plane. The positive terminal of the second ceramic capacitor is connected to the second current terminal of the power inductor, and the negative terminal of the second ceramic capacitor is connected to the simulated ground plane. The second current terminal of the power inductor is set as the output terminal of the input filtering module (1).
3. The pulse modulation circuit for an ultra-wideband supercontinuum fiber laser according to claim 1, characterized in that, The low dropout linear regulator module (2) includes an LDO regulator, a current-limiting resistor, a third ceramic capacitor, and a fourth ceramic capacitor. The voltage input terminal of the LDO regulator is connected to the output terminal of the input filter module (1). The enable control terminal of the LDO regulator is used to connect to an external enable signal. The ground terminal of the LDO regulator is connected to the analog ground plane. The first conductive terminal of the current-limiting resistor is connected to the voltage output terminal of the LDO regulator. The positive terminals of the third and fourth ceramic capacitors are both connected to the second conductive terminal of the current-limiting resistor. The negative terminals of the third and fourth ceramic capacitors are both connected to the analog ground plane. The second conductive terminal of the current-limiting resistor is set as the output terminal of the low dropout linear regulator module (2).
4. The pulse modulation circuit of an ultra-broadband supercontinuum fiber laser according to claim 1, wherein, The π-type filter module (3) includes a high-frequency ferrite bead, a fifth ceramic capacitor, a sixth ceramic capacitor, and a seventh ceramic capacitor. The first signal terminal of the high-frequency ferrite bead is connected to the output terminal of the low-dropout linear regulator module (2). The positive terminal of the fifth ceramic capacitor is connected to the first signal terminal of the high-frequency ferrite bead. The positive terminals of the sixth and seventh ceramic capacitors are both connected to the second signal terminal of the high-frequency ferrite bead. The negative terminals of the fifth, sixth, and seventh ceramic capacitors are all connected to the simulated ground plane. The second signal terminal of the high-frequency ferrite bead is set as the output terminal of the π-type filter module (3).
5. The pulse modulation circuit of an ultra-broadband supercontinuum fiber laser according to claim 1, wherein, The clock power supply distribution module (4) includes a zero-ohm resistor, an HMC7044LP10GE clock generator, a first decoupling capacitor, and a second decoupling capacitor. The first conductive end of the zero-ohm resistor is connected to the output end of the π-type filter module (3). The analog power supply end of the HMC7044LP10GE clock generator is connected to the second conductive end of the zero-ohm resistor. The digital power supply end of the HMC7044LP10GE clock generator is connected to the second conductive end of the zero-value impedance element. The positive terminal of the first decoupling capacitor is connected to the analog power supply end of the HMC7044LP10GE clock generator. The negative terminal of the first decoupling capacitor is connected to the analog ground terminal of the HMC7044LP10GE clock generator. The positive terminal of the second decoupling capacitor is connected to the digital power supply end of the HMC7044LP10GE clock generator. The negative terminal of the second decoupling capacitor is connected to the digital ground terminal of the HMC7044LP10GE clock generator. The digital ground terminal of the HMC7044LP10GE clock generator is connected to the digital ground plane.