CN214754673U

CN214754673U - Laser driving circuit

Info

Publication number: CN214754673U
Application number: CN202120482117.3U
Authority: CN
Inventors: 张松伟; 朱成清; 欧阳鸿飞; 林小龙
Original assignee: Guangdong Qitime Electrical Technology Co ltd
Current assignee: Guangdong Qitime Electrical Technology Co ltd
Priority date: 2021-03-06
Filing date: 2021-03-06
Publication date: 2021-11-16
Anticipated expiration: 2031-03-06

Abstract

The utility model discloses a laser instrument drive circuit, based on temperature measurement module, the AD converter, a microprocessor, the DA converter, the gating switch module, the pulse generation module is mutually supported, realize the drive of laser instrument, and obtain suitable waveform by gating switch module and pulse generation module, especially can obtain the waveform that pulse width is narrower, make the series resistance Rs (T) of laser instrument change because even the change of temperature, its capacity can still be controlled in the settlement range, thereby can rectify the luminous power who rectifies semiconductor laser according to the resistance correction of laser instrument.

Description

Laser driving circuit

Technical Field

The utility model belongs to the technical field of the laser instrument technique and specifically relates to indicate a laser instrument drive circuit.

Background

The laser has small volume, light weight, high luminous intensity, fast response speed and easy modulation, is an ideal device for realizing long-distance large-capacity information transmission, and is also one of the key factors for determining the reliability of an optical fiber communication system. Lasers have a wide range of applications, such as laser ranging, lidar, pulse doppler imaging, fiber optic temperature sensors, and the like. However, the pulse width of the conventional laser driving circuit is too wide, and the requirements of the application occasions of the laser cannot be met.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention is directed to a laser driving circuit, which is a conventional laser driving circuit.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a laser driving circuit comprises

The temperature measuring module consists of a temperature measuring element and a diode;

the AD converter is electrically connected with the temperature measuring module and used for receiving the detection value of the temperature measuring module and converting the detection value into a digital signal which can be identified by the microprocessor;

the microprocessor is electrically connected with the AD converter and is connected with a memory, the microprocessor calculates the temperature value detected by the temperature measuring module, extracts the corresponding temperature compensation coefficient according to the temperature value and outputs the temperature compensation coefficient after matching;

a DA converter electrically connected to the output of the microprocessor;

the gating switch module is electrically connected to the DA converter;

and the pulse generation module comprises a plurality of current sources, MOS (metal oxide semiconductor) tubes, a pull-down resistor, a capacitor and a high-frequency signal source, wherein the high-frequency signal source is electrically connected with the current sources and the MOS tubes, each MOS tube is electrically connected with the gating switch module, and the MOS tubes, the pull-down resistor and the capacitor form a variable filter and output the variable filter to the laser.

Preferably, the laser is a semiconductor laser.

Preferably, the equivalent circuit of the laser comprises an inductor L, a capacitor C, and a resistor rs (t) that changes with temperature, wherein the capacitor C is connected in parallel with the resistor rs (t) and then connected in series with the inductor L.

Preferably, the gate switch module includes four gate switches Z1, Z2, Z3 and Z4, the 1 st input of each gate switch is connected to the D/a converter, the 2 nd input is connected to the high frequency signal source, the outputs of each gate switch Z1, Z2, Z3 and Z4 are connected to the gate of each MOS transistor, the source of each MOS transistor is connected to the corresponding capacitors C1, C2, C3 and C4, the drain of each MOS transistor is grounded, the source and drain of each MOS transistor are indirectly connected to the corresponding pull-down resistors R1, R2, R3 and R4, and the capacitors C1, C2, C3 and C4 are connected to the laser.

Preferably, the current sources are four, I1, I2, I3 and I4, wherein the current source I2 is connected in series to a controllable switch K2, and the controllable switch K2 is controlled by an input signal W2; the current source I3 is connected in series with a controllable switch K3, and the controllable switch K3 is controlled by an input signal W3; the current source I4 is connected in series to a controllable switch K4, the controllable switch K4 being controlled by an input signal W4.

Compared with the prior art, the utility model obvious advantage and beneficial effect have, particularly speaking, can know by above-mentioned technical scheme, based on temperature measurement module, the AD converter, microprocessor, the DA converter, the gating switch module, the pulse generation module is mutually supported, realize the drive of laser instrument, and obtain suitable waveform by gating switch module and pulse generation module, especially can obtain the waveform that pulse width is narrower, make the series resistance Rs (T) of laser instrument change because of the change of even temperature, its capacity still can be controlled in the settlement within range, thereby can correct the luminous power of semiconductor laser instrument according to the resistance correction of laser instrument.

To illustrate the structural features and functions of the present invention more clearly, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Drawings

Fig. 1 is a circuit diagram of an embodiment of the present invention.

The attached drawings indicate the following:

10. temperature measurement module 20 and AD converter

30. Microprocessor 40, DA converter

50. Gating switch module 60 and pulse generation module

70. A laser.

Detailed Description

Referring to fig. 1, it shows a specific structure of a preferred embodiment of the present invention, which is a laser driving circuit, including a temperature measuring module 10, an AD converter 20, a microprocessor 30, a DA converter 40, a gate switch module 50, and a pulse generating module 60, all of which act on a laser 70 together to drive the laser 70, and simultaneously, the laser can support a higher speed.

The temperature measuring module 10 is configured to detect a real-time temperature of the laser 70, and calculate a value T by detecting a resistance change of an internal resistor of the laser 70 to calculate a corresponding voltage or current change. In this embodiment, the temperature measuring module 10 is composed of a temperature measuring element Rx and a diode Dx.

The AD converter 20 is electrically connected to the temperature measuring module 10, and is configured to receive the detection value T of the temperature measuring module 10 and convert the detection value T into a digital signal that can be recognized by the microprocessor 30.

The microprocessor 30 is electrically connected to the AD converter 20, the microprocessor 30 is connected to a memory, the microprocessor 30 calculates a temperature value detected by the temperature measuring module 10, and extracts a corresponding temperature compensation coefficient from the memory according to the temperature value for matching and outputting.

The DA converter 40 is electrically connected to an output of the microprocessor 30 to convert a digital signal of the microprocessor 30 into an analog signal. The gating switch module 50 is electrically connected to the DA converter 40, and is configured to gate signals of the microprocessor 30 and the high-frequency signal source to corresponding MOS transistors, and control on/off of different MOS transistors to output different pulse currents to the laser 70.

The pulse generating module 60 includes a plurality of current sources, MOS transistors, pull-down resistors and capacitors, and a high frequency signal source. The high-frequency signal source is electrically connected with the current source and the MOS transistors, each MOS transistor is electrically connected with the gating switch module 50, and the MOS transistor, the pull-down resistor and the capacitor form a variable filter and output the variable filter to the laser 70.

For example, without any intervention, the pulse interval of the circuit is TW, the pulse width is adjusted to TW/2 when MOS 1 is gated, TW/4 when MOS 2 is gated, TW/8 when MOS 3 is gated, and so on. Therefore, when it is detected that the temperature value is variable, the microprocessor 30 selects the corresponding channel to correct the pulse signal so that the distortion is reduced and the flux becomes larger, so that it reaches the acceleration of the laser 70 at a larger flux.

In this embodiment, the laser 70 is a semiconductor laser. The equivalent circuit of the laser 70 includes an inductor L, a capacitor C, and a resistor rs (t) that changes with temperature, wherein the capacitor C is connected in parallel with the resistor rs (t) and then connected in series with the inductor L. The gating switch module 50 includes four gating switches Z1, Z2, Z3 and Z4, the 1 st input of each gating switch is connected to the D/a converter, the 2 nd input is connected to the high frequency signal source, the outputs of each gating switch Z1, Z2, Z3 and Z4 are connected to the gate of each MOS transistor, the source of each MOS transistor is connected to the corresponding capacitor C1, C2, C3 and C4, the drain of each MOS transistor is grounded, the source and drain of each MOS transistor are indirectly connected to the corresponding pull-down resistor R1, R2, R3 and R4, and each capacitor C1, C2, C3 and C4 are connected to the laser 70.

The current sources are four, I1, I2, I3 and I4, wherein the current source I2 is connected in series to a controllable switch K2, and a controllable switch K2 is controlled by an input signal W2; the current source I3 is connected in series with a controllable switch K3, and the controllable switch K3 is controlled by an input signal W3; the current source I4 is connected in series to a controllable switch K4, the controllable switch K4 being controlled by an input signal W4.

The current sources I2, I3, I4 record signals according to signals W2, W3, W4, respectively. When the signals W2, W3, W4 are low, only the current source I1 provides the laser 70 with a current signal, and when the signals W2, W3, W4 become high, respectively, the corresponding current sources I2, I3, I4 provide the laser 70 with a current signal; the change of the signals W2, W3, and W4 is determined by an external signal, and for example, an external controller may be added, and the levels of the signals W2, W3, and W4 change in the case of setting. And by controlling the conduction of the corresponding MOS transistor, the change of the pulse frequency is achieved, so that the frequency acting on the laser 70 is selectable. To obtain an appropriate waveform such that the series resistance rs (t) of the laser 70 can be controlled within a set range due to the change in the capacitance even if the temperature changes, so that the light emission power of the semiconductor laser 70 can be corrected according to the resistance correction of the laser 70.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any slight modifications, equivalent changes and modifications made by the technical spirit of the present invention to the above embodiments are all within the scope of the technical solution of the present invention.

Claims

1. A laser driver circuit, characterized by: comprises that

The temperature measuring module (10) consists of a temperature measuring element and a diode;

the AD converter (20) is electrically connected with the temperature measuring module (10) and is used for receiving the detection value of the temperature measuring module (10) and converting the detection value into a digital signal which can be identified by the microprocessor (30);

the microprocessor (30) is electrically connected with the AD converter (20), the microprocessor (30) is connected with a memory, the microprocessor (30) calculates the temperature value detected by the temperature measuring module (10), and extracts the corresponding temperature compensation coefficient according to the temperature value to be matched and then outputs the temperature value;

a DA converter (40) electrically connected to the output of the microprocessor (30);

a gating switch module (50) electrically connected to the DA converter (40);

and the pulse generation module (60) comprises a plurality of current sources, MOS (metal oxide semiconductor) tubes, pull-down resistors, capacitors and a high-frequency signal source, wherein the high-frequency signal source is electrically connected with the current sources and the MOS tubes, each MOS tube is electrically connected with the gating switch module (50), and the MOS tubes, the pull-down resistors and the capacitors form a variable filter to be output to the laser (70).

2. A laser driver circuit according to claim 1, wherein: the laser (70) is a semiconductor laser.

3. A laser driver circuit according to claim 2, wherein: the equivalent circuit of the laser (70) comprises an inductor L, a capacitor C and a resistor Rs (T) which changes along with temperature change, wherein the capacitor C is connected with the resistor Rs (T) in parallel and then connected with the inductor L in series.

4. A laser driver circuit according to claim 1, wherein: the gating switch module (50) comprises four gating switches Z1, Z2, Z3 and Z4, the 1 st input of each gating switch is connected to the D/A converter, the 2 nd input of each gating switch is connected to the high-frequency signal source, the outputs of each gating switch Z1, Z2, Z3 and Z4 are connected to the grid of each MOS tube, the source of each MOS tube is connected to the corresponding capacitor C1, C2, C3 and C4, the drain of each MOS tube is grounded, a pull-down resistor R1, R2, R3 and R4 are indirectly connected between the source and the drain of each MOS tube, and each capacitor C1, C2, C3 and C4 are connected to the laser (70).

5. A laser driver circuit according to claim 4, wherein: the current sources are four, I1, I2, I3 and I4, wherein the current source I2 is connected in series to a controllable switch K2, and a controllable switch K2 is controlled by an input signal W2; the current source I3 is connected in series with a controllable switch K3, and the controllable switch K3 is controlled by an input signal W3; the current source I4 is connected in series to a controllable switch K4, the controllable switch K4 being controlled by an input signal W4.