CN203014759U - Filter drive circuit of swept source - Google Patents
Filter drive circuit of swept source Download PDFInfo
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- CN203014759U CN203014759U CN 201220689602 CN201220689602U CN203014759U CN 203014759 U CN203014759 U CN 203014759U CN 201220689602 CN201220689602 CN 201220689602 CN 201220689602 U CN201220689602 U CN 201220689602U CN 203014759 U CN203014759 U CN 203014759U
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- filter
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- sine wave
- drive circuit
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Abstract
The utility model provides a filter drive circuit of a swept source. The filter drive circuit comprises a signal generation circuit, a filter circuit, a gain adjusting circuit, and a filter load, wherein the signal generation circuit is used for generating sine wave signals; an input terminal of the filter circuit is connected to an output terminal of the signal generation circuit; the filter circuit is used for filtering out noises outside the frequency band of the sine wave signals; an input terminal of the gain adjusting circuit is connected to an output terminal of the filter circuit, while an output terminal of the gain adjusting circuit is connected to the filter load; and the gain adjusting circuit is used for amplifying mixing waveforms of the sine wave signals and narrowband noises. With the adoption of the filter drive circuit, the output frequency is enabled to be adjustable between 20 KHz and 200 KHz continuously, the peak-to-peak value voltage can reach 3 V, the phase is also adjustable, the output load is about 1 omega, the stability of the filter load is guaranteed, the requirements of different laser devices on modulation amplitudes are met, and the coordinability of the wavelength of swept lasers is realized.
Description
Technical field
The utility model relates to frequency sweep optical coherent chromatographic imaging and sensory field of optic fibre, particularly a kind of filter drive circuit of swept light source.
Background technology
Swept light source is the light source of timesharing output different wave length monochromatic wave on time domain, it is by the rapid scanning of narrowband wavelength filter, at a time a monochromatic wave with a certain fixed wave length parses from broadband spectral, quick to realize, narrow instantaneous live width and linear broadband frequency sweep output, can be widely used in the fields such as optical coherence tomography (Optical Coherence Tomography is called for short OCT) and Fibre Optical Sensor.Wherein, as the Primary Component of swept light source, the driving of filter is most important to the parameter of swept light source.
Realize swept light source, one of mode is that the deformation by filter changes cavity length to reach the tunable of sweeping laser wavelength; Need to add different frequency and different voltage to filter like this, to reach the different modulation amplitude of laser.According to filter characteristic, reach the requirement of swept light source fast wave long scan, need to surpass the pumping signal of 50KHz to filter plus signal frequency in real system, still, existing signal generation apparatus can't satisfy this demand.
The existing device that can be used as filter driving signal is divided into two kinds, a kind of is that peak-to-peak value is adjustable, and frequency is adjustable, but output current power is lower, output impedance generally can only reach 50 ohm of left and right, can't stabilized driving operates in the filter driver of the similar signal generator under high frequency; A kind of is that it is adjustable that this driver has frequency by the special filter driver of filter manufacturers design, the characteristics such as working stability, but this scheme output waveform frequency is inadequate.
The utility model content
For the deficiencies in the prior art, the utility model provides a kind of filter drive circuit of swept light source, makes the frequency of its output can be at 20KHz to adjustable continuously between 200KHz, and peak-to-peak value voltage can reach 3V, and phase place is also adjustable, and its output loading is in 1 left and right, Europe.
For realizing above function, the utility model is achieved by the following technical programs:
A kind of filter drive circuit of swept light source includes signal generating circuit, filter circuit, gain adjustment circuit and filter load;
Described signal generating circuit, for generation of sine wave signal, described sine wave signal amplitude is consistent, frequency is adjustable;
The input of described filter circuit is connected in the output of described signal generating circuit, and this filter circuit is used for the noise beyond the described sine wave signal frequency band of filtering, and the hybrid waveform of sine wave output signal and narrow-band noise;
The input of described gain adjustment circuit is connected with the output of described filter circuit, and the output of described gain adjustment circuit connects filter load; This gain adjustment circuit is used for the hybrid waveform of described sine wave signal and narrow-band noise is amplified, the sine wave output amplifying signal.
Further comprise the phase bias Circuit tuning after described signal generating circuit, the output of described phase bias Circuit tuning is connected in the input of described filter circuit, and described phase bias Circuit tuning is used for described sine wave signal is carried out the phase place adjustment.
Described phase bias Circuit tuning adopts external adder circuit to realize.
Described signal generating circuit is sinusoidal oscillator or Direct Digital Synthesizer;
The method that described sinusoidal oscillator utilizes master controller to adjust in real time frequency of oscillation is adjusted the frequency of described sinusoidal oscillator.
Described filter circuit is active filter or passive filter; Described filter circuit is low pass circuit or band-pass circuit.
Described gain adjustment circuit is amplifying circuit or auto-gain circuit.
The output of described gain adjustment circuit further is connected with the driving intensifier circuit that comprises amplifier, and this output that drives intensifier circuit connects filter load.
Described driving intensifier circuit further comprises the amplifier Circuit tuning, and described amplifier Circuit tuning is used for controlling the amplifier of described driving intensifier circuit, can stablize under unit gain.
The output of described driving intensifier circuit further is connected with thermostat module, and described filter load is placed in the insulating box of this thermostat module; Described thermostat module is regulated the temperature of described filter load by gathering the actual temperature of filter load.
Described thermostat module comprises controlled source, design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box;
Described design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box all are connected to described controlled source;
Described design temperature circuit be connected temperature sensor and be connected with described temperature controller respectively, described temperature controller, thermoregulator and insulating box connect successively; Described filter load is located in described insulating box.
The utility model is by providing a kind of filter drive circuit of swept light source, makes the frequency of its output can be at 20KHz to adjustable continuously between 200KHz, and peak-to-peak value voltage can reach 3V, and phase place is also adjustable, and its output loading is in 1 left and right, Europe; Guarantee the stability of filter load, satisfied various lasers to the requirement of modulation amplitude, reached the tunable of sweeping laser wavelength.
Description of drawings
Fig. 1 is the filter drive circuit block diagram of the utility model one embodiment;
Fig. 2 is the sinusoidal oscillator of the utility model one embodiment;
Fig. 3 is the active second-order filter circuit of the utility model one embodiment;
Fig. 4 is the passive single order RC low-pass filter circuit of the utility model one embodiment;
Fig. 5 is the amplifying circuit of the utility model one embodiment;
Fig. 6 is the auto-gain circuit theory diagram of the utility model one embodiment;
Fig. 7 is the filter drive circuit block diagram of the utility model the second embodiment;
Fig. 8 is the driving intensifier circuit of the utility model the second embodiment;
Fig. 9 is another driving intensifier circuit of the utility model the second embodiment;
Figure 10 is the amplifier Circuit tuning of the utility model the second embodiment;
Figure 11 is the filter drive circuit block diagram of the utility model the 3rd embodiment.
Embodiment
Under regard to the filter drive circuit of a kind of swept light source that the utility model proposes, describe in detail in conjunction with the accompanying drawings and embodiments.
Embodiment 1:
As shown in Figure 1, the present embodiment provides a kind of filter drive circuit of swept light source, includes signal generating circuit, filter circuit, gain adjustment circuit and filter load;
Described signal generating circuit, for generation of sine wave signal, described sine wave signal amplitude is consistent, frequency is adjustable;
The input of described filter circuit is connected in the output of described signal generating circuit, and this filter circuit is used for the noise beyond the described sine wave signal frequency band of filtering, and the hybrid waveform of sine wave output signal and narrow-band noise;
The input of described gain adjustment circuit is connected with the output of described filter circuit, and the output of described gain adjustment circuit connects filter load; This gain adjustment circuit is used for the hybrid waveform of described sine wave signal and narrow-band noise is amplified, the sine wave output amplifying signal.
Described signal generating circuit is sinusoidal oscillator or Direct Digital Synthesizer; The method that described sinusoidal oscillator utilizes master controller to adjust in real time frequency of oscillation is adjusted the frequency of described sinusoidal oscillator.
As shown in Figure 2, described sinusoidal oscillator comprises a bipolarity operational amplifier 1, and the in-phase end of this bipolarity operational amplifier 1 is connected with resistance R 1, capacitor C 1, the other end ground connection of described resistance R 1, capacitor C 1; The feedback loop of the in-phase end of this bipolarity operational amplifier 1 is in series by capacitor C 2, resistance R 2; Ground connection after the end of oppisite phase of this bipolarity operational amplifier 1 is connected with resistance R 3, and the end of oppisite phase of this bipolarity operational amplifier 1 be connected to output V after resistance R 4 is connected
oThe frequency of oscillation W=1/RC of described sinusoidal oscillator is determined by the RC series network with selecting frequency characteristic; Namely by resistance R 1, capacitor C 1 and capacitor C 2, the product of resistance R 2 determines.The starting condition for oscillation of described sinusoidal oscillator is A〉3, namely require the voltage gain of amplifier more than or equal to 3, being slightly larger than 3 reason is due to the various losses in circuit, causes amplitude descend and recompense.But A much bigger can cause sine wave output deformation poor than 3; Similar principle, typical sinusoidal oscillator also can be by fet oscillator or capacitance connecting three point type oscillator, and inductance connecting three point type forms.
Because described filter drive circuit need to have the adjustable frequency function, therefore need the frequency of oscillation of offset of sinusoidal oscillator dynamically to adjust, namely need resistance R shown in Figure 21, capacitor C 1, capacitor C 2, resistance R 2 is adjusted; The method of utilizing in the present embodiment described master controller to adjust in real time frequency of oscillation is adjusted in real time to frequency of oscillation; The method is that the resistance R 1 in Fig. 2 and resistance R 2 are replaced with digital regulation resistance, and digital regulation resistance is a kind of digital adjustable resistance, can change in real time easily parameter; For guaranteeing accurate frequency of oscillation, need to select precision resister, need to have 1% with interior precision, the low gain error can be provided in whole resistance range.
Can adjust easily frequency, phase place by Direct Digital Synthesizer DDS, and control precision is high, the frequency switch speed fast, phase place can freely be adjusted.
The waveform that produces due to sinusoidal oscillator or Direct Digital Synthesizer is that amplitude is consistent, the sine wave signal that frequency is adjustable, also need pass through the phase bias Circuit tuning, further comprise the phase bias Circuit tuning after described signal generating circuit, the output of described phase bias Circuit tuning is connected in the input of described filter circuit, and described phase bias Circuit tuning is used for described sine wave signal is carried out the phase place adjustment; Described phase bias Circuit tuning adopts external adder circuit to realize, due to comparatively general, is not therefore given unnecessary details in the present embodiment.
Described filter circuit is active filter or passive filter; Described filter circuit is low pass circuit or band-pass circuit, common circuit is active second-order filter circuit and typical passive single order RC low-pass filter circuit, described active second-order filter circuit is typical Sallen-Key low-pass filter circuit connection, and its annexation as shown in Figure 3; This operational amplifier 2 is for homophase excites, and the input impedance of filter is higher, and output impedance is lower, and circuit performance is stable, and gain is easily adjusted.Also can form the filter of band pass filter or other exponent number through similar design.
The annexation of described passive single order RC low-pass filter circuit as shown in Figure 4; This low pass filter can provide the speed of roll-offing of 20db after corner frequency, similarly design also can form LC low pass circuit, LC bandwidth-limited circuit; Wherein, the time constant that is comprised of resistance R 9 and capacitor C 5 forms the corner frequency of this low pass filter.
Described filter circuit can suppress the out-of-band noise of described sine wave signal, reduces the problems such as wave distortion, hydraulic performance decline.
Described gain adjustment circuit is amplifying circuit or auto-gain circuit.Be illustrated in figure 5 as amplifying circuit; Can carry out signal by in-phase amplification circuit or see-saw circuit amplifies; In adjusting figure, feedback resistance R12 can change the peak-to-peak value amplitude of multiplication factor and then control filter driver output waveform; The difference of in-phase amplification circuit and see-saw circuit is that the output signal of in-phase amplification circuit is identical with the phase place of input signal, and see-saw circuit differs 180 degree.
Be illustrated in figure 6 as auto-gain circuit (AGC) theory diagram; By controlling G+, the voltage of G-, output waveform that can the real time altering amplifier circuit.
Embodiment 2:
The filter drive circuit of a kind of swept light source that the present embodiment provides is identical with technical scheme described in embodiment 1, as shown in Figure 7, the output that is described gain adjustment circuit further is connected with the driving intensifier circuit that comprises amplifier, and this output that drives intensifier circuit connects filter load; This driving intensifier circuit is used for reducing the impedance of described sinusoidal wave amplifying signal, strengthens driving force.
Through embodiment 1 described drive circuit, obtained satisfactory signal waveform, but the amplifier of described gain adjustment circuit exports that often output resistance is larger, driving force is not enough.Drive the high frequency capacitive load, special driving intensifier circuit need to be arranged, this circuit has that output impedance is little, and gain bandwidth product is large, supports the characteristics such as bipolarity high voltage drive.
Fig. 8 and Fig. 9 are two kinds of driving intensifier circuits.As shown in Figure 8, be to adopt the method for amplifier host-slave parallel to drive enhancing; By the given end of oppisite phase that is linked into amplifier 5, R13 one end ground connection, the in-phase end of other end concatenation operation amplifier 5; The output of described operational amplifier 5 is connected with the in-phase end of operational amplifier 6, and described operational amplifier 6 is homophase follower connection, access load resistance R15 after being connected with the resistance R 14 of operational amplifier 5 in-phase ends with resistance R 17 by balance resistance R16.Fig. 9 adopts the outside circuit that promotes to drive enhancing; What adopt is the push-pull connection method of the rear access triode of operational amplifier 7; Resistance R 18, resistance R 19 and resistance R 23 are used for the matched static balance point, and resistance R 20, resistance R 21 and resistance R 22 are current-limiting resistances; Capacitor C 6 is electric capacity by way of compensation, regulates frequency and the phase characteristic of amplifier.
What pay special attention to is, some amplifiers can't be stable and the voltage-tracing pattern, and therefore, described driving intensifier circuit further comprises the amplifier Circuit tuning, described amplifier Circuit tuning is used for controlling the amplifier of described driving intensifier circuit, can stablize under unit gain.
Described amplifier Circuit tuning as shown in figure 10, the anti-phase connection of the amplifier of employing, the end of oppisite phase of resistance R 24 and capacitor C 8 access operational amplifiers 14 is regulated cut-off frequency in the feedback control loop of resistance R 25 and capacitor C 7 access operational amplifiers 14; When low gain, the noise of amplifier also will come by control capacittance C7, capacitor C 8, resistance R 24 and resistance R 25 noise of balance different frequency simultaneously; Make operational amplifier stable under unit gain by adjustment capacitor C 7, capacitor C 8; Also can adopt in addition the small-signal response method that circuit parameter is optimized in real system.
Embodiment 3:
In actual motion, the stability of filter there is strict requirement, in numerous influencing factors, temperature is to play an important role.Therefore need to add thermostat module to guarantee the consistency of temperature.The filter drive circuit of a kind of swept light source that the present embodiment provides, on the basis of above embodiment, as shown in figure 11, the output of described driving intensifier circuit further is connected with thermostat module, and described filter load is placed in the insulating box of this thermostat module; Described thermostat module is regulated the temperature of described filter load, to guarantee the temperature stabilization of described filter by gathering the actual temperature of filter load.
Described thermostat module comprises controlled source, design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box;
Described temperature controller comprises subtracter, proportional amplifier, integral amplifier, differentiating amplifier, adder;
Described design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box all are connected to described controlled source;
Described design temperature circuit be connected temperature sensor and be connected with described temperature controller respectively, described temperature controller, thermoregulator and insulating box connect successively; Described filter load is located in described insulating box.
Drawn by above embodiment, the utility model is by providing a kind of filter drive circuit of swept light source, makes the frequency of its output can be at 20KHz to adjustable continuously between 200KHz, and peak-to-peak value voltage can reach 3V, phase place is also adjustable, and its output loading is in 1 left and right, Europe; Guarantee the stability of filter load, satisfied various lasers to the requirement of modulation amplitude, reached the tunable of sweeping laser wavelength.
Above execution mode only is used for explanation the utility model; and be not limitation of the utility model; the those of ordinary skill in relevant technologies field; in the situation that do not break away from spirit and scope of the present utility model; can also make a variety of changes and modification; therefore all technical schemes that are equal to also belong to category of the present utility model, and scope of patent protection of the present utility model should be defined by the claims.
Claims (10)
1. the filter drive circuit of a swept light source, is characterized in that, includes signal generating circuit, filter circuit, gain adjustment circuit and filter load;
Described signal generating circuit, for generation of sine wave signal, described sine wave signal amplitude is consistent, frequency is adjustable;
The input of described filter circuit is connected in the output of described signal generating circuit, and this filter circuit is used for the noise beyond the described sine wave signal frequency band of filtering, and the hybrid waveform of sine wave output signal and narrow-band noise;
The input of described gain adjustment circuit is connected with the output of described filter circuit, and the output of described gain adjustment circuit connects filter load; This gain adjustment circuit is used for the hybrid waveform of described sine wave signal and narrow-band noise is amplified, the sine wave output amplifying signal.
2. drive circuit as claimed in claim 1, it is characterized in that, further comprise the phase bias Circuit tuning after described signal generating circuit, the output of described phase bias Circuit tuning is connected in the input of described filter circuit, and described phase bias Circuit tuning is used for described sine wave signal is carried out the phase place adjustment.
3. drive circuit as claimed in claim 2, is characterized in that, described phase bias Circuit tuning adopts external adder circuit to realize.
4. drive circuit as described in the claims 1 to 3 any one, is characterized in that, described signal generating circuit is sinusoidal oscillator or Direct Digital Synthesizer;
The method that described sinusoidal oscillator utilizes master controller to adjust in real time frequency of oscillation is adjusted the frequency of described sinusoidal oscillator.
5. drive circuit as claimed in claim 1, is characterized in that, described filter circuit is active filter or passive filter; Described filter circuit is low pass circuit or band-pass circuit.
6. drive circuit as claimed in claim 1, is characterized in that, described gain adjustment circuit is amplifying circuit or auto-gain circuit.
7. drive circuit as claimed in claim 1, is characterized in that, the output of described gain adjustment circuit further is connected with the driving intensifier circuit that comprises amplifier, and this output that drives intensifier circuit connects filter load.
8. drive circuit as claimed in claim 8, is characterized in that, described driving intensifier circuit further comprises the amplifier Circuit tuning, and described amplifier Circuit tuning is used for controlling the amplifier of described driving intensifier circuit, can stablize under unit gain.
9. drive circuit as claimed in claim 7 or 8, is characterized in that, the output of described driving intensifier circuit further is connected with thermostat module, and described filter load is placed in the insulating box of this thermostat module; Described thermostat module is regulated the temperature of described filter load by gathering the actual temperature of filter load.
10. drive circuit as claimed in claim 9, is characterized in that, described thermostat module comprises controlled source, design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box;
Described design temperature circuit, temperature sensor, temperature controller, thermoregulator and insulating box all are connected to described controlled source;
Described design temperature circuit be connected temperature sensor and be connected with described temperature controller respectively, described temperature controller, thermoregulator and insulating box connect successively; Described filter load is located in described insulating box.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220689602 CN203014759U (en) | 2012-12-13 | 2012-12-13 | Filter drive circuit of swept source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220689602 CN203014759U (en) | 2012-12-13 | 2012-12-13 | Filter drive circuit of swept source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203014759U true CN203014759U (en) | 2013-06-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220689602 Expired - Lifetime CN203014759U (en) | 2012-12-13 | 2012-12-13 | Filter drive circuit of swept source |
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| CN (1) | CN203014759U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066485A (en) * | 2012-12-13 | 2013-04-24 | 乐普（北京）医疗器械股份有限公司 | Filter drive circuit of swept source |
| CN115494906A (en) * | 2022-09-19 | 2022-12-20 | 北京大学 | Amplitude and phase adjustable VCSEL alternating current modulation circuit and integrated circuit |
-
2012
- 2012-12-13 CN CN 201220689602 patent/CN203014759U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103066485A (en) * | 2012-12-13 | 2013-04-24 | 乐普（北京）医疗器械股份有限公司 | Filter drive circuit of swept source |
| CN103066485B (en) * | 2012-12-13 | 2015-03-25 | 乐普（北京）医疗器械股份有限公司 | Filter drive circuit of swept source |
| CN115494906A (en) * | 2022-09-19 | 2022-12-20 | 北京大学 | Amplitude and phase adjustable VCSEL alternating current modulation circuit and integrated circuit |
| CN115494906B (en) * | 2022-09-19 | 2023-09-12 | 北京大学 | VCSEL alternating current modulation circuit with adjustable amplitude and phase and integrated circuit |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130619 |