CN104901161A - Laser source system based on VCSEL technology - Google Patents

Abstract

The invention relates to a laser source system based on VCSEL technology, comprising: an electron gun and a VCSEL chip package, including an electron gun and a VCSEL chip; a focusing coil, installed outside the electron gun and the VCSEL chip package, for controlling the electron beam in the electron gun Refocusing; deflection coil, installed outside the electron gun and VCSEL chip package, used to control the trajectory of the electron beam in the electron gun, and control the incident orientation of the electron beam on the surface of the VCSEL chip; microcontroller, connected with the electron gun, used for Control the start and operation control of the electron gun; the scanning control unit is connected with the focusing coil and the deflection coil respectively, and is used to drive the focusing coil and the deflection coil; the central processing unit is connected with the microcontroller and the scanning control unit respectively, and is used for the whole system Run monitoring. Compared with the prior art, the invention has the advantages of high reliability, long service life, good safety and the like.

Description

A Laser Source System Based on VCSEL Technology

technical field

The invention relates to a laser source system, in particular to a laser source system based on VCSEL technology.

Background technique

Laser display is the fourth-generation display technology after black and white display, color display, and digital high-definition display; laser TV is one of its application fields. Revolutionary, its color gamut coverage can theoretically reach more than 90% of the human eye color gamut range, making the display screen more realistic, layered and transparent, and the clarity of the screen also increases significantly with the improvement of color saturation improvement.

The theory of VCSEL technology was first proposed by Basov, the winner of the Nobel Prize in Physics in 1964. It is a solid-state laser source with great potential. The bands range from infrared to deep ultraviolet. It is also expected to be widely used in optical fiber communication, laser printing, gas detection, and high-density optical storage. However, how to apply VCSEL technology to laser sources has become a technical problem that needs to be solved urgently.

Contents of the invention

The purpose of the present invention is to provide a laser source system based on VCSEL technology with high reliability, long service life, good safety and convenient operation in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A laser source system based on VCSEL technology, characterized in that it comprises:

Electron gun and VCSEL chip package, including electron gun and VCSEL chip;

The focusing coil is installed outside the electron gun and the VCSEL chip package, and is used to refocus the electron beam in the electron gun;

The deflection coil is installed outside the electron gun and the VCSEL chip package, and is used to control the trajectory of the electron beam in the electron gun and control the incident orientation of the electron beam on the surface of the VCSEL chip;

A microcontroller, connected with the electron gun, is used to control the starting and operation control of the electron gun;

The scanning control unit is connected with the focus coil and the deflection coil respectively, and is used to drive the focus coil and the deflection coil;

The central processing unit CPU is connected with the micro-controller and the scanning control unit respectively, and is used for the operation monitoring of the whole system;

The man-machine interface is connected with the CPU, the operating parameters are set through the keyboard, and the operating parameters are recorded in real time.

The electron gun is a three-stage cross gun, including an electron-emitting cathode, a G1 grid, a G2 accelerating electrode and a G3 electron focusing electrode.

A thermally conductive substrate is bonded to the bottom of the VCSEL chip.

It also includes a VCSEL semiconductor temperature control circuit respectively connected to the CPU and the substrate for controlling the temperature of the VCSEL chip.

It also includes an output driving and amplifying circuit respectively connected with the scanning control unit, the focusing coil and the deflection coil.

It also includes a focus and deflection coil current detection circuit, the focus and deflection coil current detection circuit is respectively connected with the CPU, the focus coil and the deflection coil.

The focus coils include static focus coils and dynamic focus coils, the deflection yokes include line deflection coils and field deflection coils, and the scan control unit includes:

The static focus coil power supply is connected to the CPU and the static focus coil respectively;

Scanning control circuit, connected with CPU;

The field deflection coil driving circuit is connected with the scanning control circuit and the field deflection coil respectively;

The horizontal deflection coil driving circuit is connected with the scanning control circuit and the horizontal deflection coil respectively;

The dynamic focus coil driving circuit is connected with the line deflection coil and the amplification circuit respectively, wherein the amplification circuit is connected with the dynamic focus coil.

The field deflection coil driving circuit includes a first pre-excitation circuit and a power output circuit connected in sequence, the first pre-excitation circuit is connected to the scanning control circuit, and the power output circuit is connected to the field deflection coil.

The horizontal deflection coil drive circuit includes a second pre-excitation circuit, a horizontal scanning output circuit, a sequential circuit and an electron gun electron beam blanking circuit, and the scanning control circuit is connected with the second pre-excitation circuit, the horizontal scanning output circuit, and a sequential circuit respectively. Circuit connection, the horizontal scanning output circuit is respectively connected with the second pre-excitation circuit and the horizontal deflection coil, and the horizontal deflection coil and the timing circuit are respectively connected with the electron beam blanking circuit of the electron gun.

The described dynamic focus coil drive circuit comprises a horizontal deflection coil scanning waveform sampling circuit and a dynamic correction signal generation circuit connected in sequence, the horizontal deflection coil scanning waveform sampling circuit is connected with the horizontal deflection coil, and the dynamic correction signal generation circuit Connect with the amplifier circuit.

Compared with the prior art, the present invention has the following advantages:

1) High reliability, the system uses an independent MCU control unit, and communicates with the CPU (ARM chip selected) unit, which improves the reliability of the start-up and operation control of the electron gun;

2) The service life is long, and the failure or loss of control of the scanning circuit will cause the electron beam to bombard the fixed surface of the VCSEL chip for a long time, causing damage to the chip. Therefore, the system composition includes a focusing and deflection coil current detection unit circuit to avoid damage to the chip;

3) safety is good, the energy of electron beam can not be all converted into the output of laser energy, also in order to improve the energy of laser output, need to adopt cooling measure, it is necessary to reduce chip temperature, the present invention has adopted VCSEL semiconductor temperature control circuit outside the chip, And it can be monitored by the CPU, which improves the security of the system;

4) Easy to operate. The system includes a man-machine interface function. In addition to setting operating parameters through the keyboard, it also has a real-time operating parameter recording unit, which is convenient for analyzing operating parameters and optimizing operating efficiency.

Description of drawings

Fig. 1 is a structural representation of the present invention;

FIG. 2 is a schematic structural diagram of a scanning control unit of the present invention;

FIG. 3 is a specific circuit diagram of the row scanning output circuit of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

As shown in Figure 1, a laser source system based on VCSEL technology includes:

An electron gun and a VCSEL chip package 1, including an electron gun 4 and a VCSEL chip 5;

The focusing coil 2 is installed outside the electron gun and the VCSEL chip package 1, and is used to refocus the electron beam in the electron gun;

The deflection coil 3 is installed outside the electron gun and the VCSEL chip package 1, and is used to control the trajectory of the electron beam in the electron gun and control the incident orientation of the electron beam on the surface of the VCSEL chip;

Microcontroller 6, connected with electron gun 4, is used to control the starting and operation control of electron gun;

The scan control unit 8 is connected to the focus coil 2 and the deflection coil 3 respectively, and is used to drive the focus coil and the deflection coil;

The human-machine interface 12, in addition to setting the operating parameters through the keyboard, also has a real-time operating parameter recording unit, which facilitates the analysis of operating parameters and optimizes operating efficiency;

The central processing unit CPU7 is respectively connected with the microcontroller 6 and the scanning control unit 8 for monitoring the operation of the whole system.

The electron gun 4 is a three-stage cross gun, including a cathode for emitting electrons, a G1 grid, a G2 accelerating electrode and a G3 electron focusing electrode. A thermally conductive substrate 15 is bonded to the bottom of the VCSEL chip 5 . By setting the VCSEL semiconductor temperature control circuit 11 respectively connected to the CPU and the substrate, it is used to realize the control of the temperature of the VCSEL chip. During normal operation, the cathode current is set to 400mA, and the maximum value of G3 is 3.5kV.

The present invention also includes an output driving and amplifying circuit 11 connected to the scanning control unit 8, the focusing coil 2 and the deflection coil 3, respectively. And also includes focus and deflection coil current detection circuit 10, the focus and deflection coil current detection circuit 10 is connected with CPU7, focus coil 2 and deflection coil 3 respectively.

As shown in Figure 2, the focus coil 2 includes a static focus coil 21 and a dynamic focus coil 22, and the deflection coil 3 includes a line deflection coil 32 and a field deflection coil 31;

Described scanning control unit 8 comprises:

Static focus coil power supply 82 is connected with CPU7 and static focus coil 21 respectively;

Scanning control circuit 81 is connected with CPU7;

The field deflection coil driving circuit is connected with the scanning control circuit 81 and the field deflection coil respectively;

The line deflection coil driving circuit is connected with the scanning control circuit 81 and the line deflection coil respectively;

The dynamic focus coil driving circuit is connected with the line deflection coil and the amplification circuit respectively, wherein the amplification circuit is connected with the dynamic focus coil.

The field deflection coil drive circuit includes a first pre-excitation circuit 83 and a power output circuit 84 connected in sequence, the first pre-excitation circuit 83 is connected to the scanning control circuit 81, and the power output circuit 84 is connected to the field deflection coil 31 connections.

The horizontal deflection coil drive circuit includes a second pre-excitation circuit 85, a row scan output circuit 86, a sequential circuit 87 and an electron gun electron beam blanking circuit 88, and the scanning control circuit 81 is connected with the second pre-excitation circuit 85, The line scanning output circuit 86 and the timing circuit 87 are connected, and the line scanning output circuit 86 is connected with the second pre-excitation circuit 85 and the line deflection coil 32 respectively, and the line deflection coil 32 and the sequence circuit 87 are connected with the electron beam of the electron gun respectively. Blanking circuit 88 is connected.

The described dynamic focus coil driving circuit comprises a horizontal deflection coil scanning waveform sampling circuit 891 and a dynamic correction signal generation circuit 892 connected in sequence, and the horizontal deflection coil scanning waveform sampling circuit 891 is connected with the horizontal deflection coil 32, and the dynamic The correction signal generation circuit 892 is connected to the amplification circuit.

In order to improve the reliability of the start-up and operation control of the electron gun, the system adopts an independent MCU control unit, and communicates with the CPU (ARM chip selected) unit; the CPU unit is the core of the whole system, controls the scanning control unit, and generates electron beam scanning and trajectory compensation control signal, through the output amplifier circuit, to drive the focusing and deflection coils; the failure or loss of control of the scanning circuit will cause the electron beam to bombard the fixed surface of the VCSEL chip for a long time, causing damage to the chip. Therefore, the system composition includes focusing and deflection Coil current detection unit circuit; the energy of the electron beam cannot be completely converted into the output of laser energy, and in order to increase the energy of the laser output, cooling measures are required, and it is necessary to reduce the chip temperature. The CPU is monitored.

This system includes the man-machine interface function. In addition to setting the operating parameters through the keyboard, it also has a real-time operating parameter recording unit, which facilitates the analysis of operating parameters and optimizes operating efficiency.

As shown in Figure 1, the VCSEL chip has a planar structure. In order to effectively output the laser light generated by the VCSEL chip, its plane normal and the axis of the electron gun form an angle of approximately 45°. This structural arrangement currently adopted is different from that of the traditional CRT electron beam Compared with the scanning structure, it greatly increases the design difficulty of the electron beam scanning trajectory control, so the design of the scanning control circuit is also a key technical problem to be solved in this system.

Realization of key control circuits

1) Electronic gun control circuit description

Under the condition that the scanning control circuit works normally, start the electron gun again. The starting process control of the electron gun is very important, and the automatic control is realized by the microcontroller. The cathode filament current is initially set to 50% of the normal value, about 200mA, and the initial value of the grid voltage of G1 is small, not greater than 150V; after the voltages of G2 and G3 are gradually increased to 800V and 3.5kV of the normal working voltage , by adjusting the G1 grid voltage value, the current density of the electron beam can be adjusted, and the design value of the current density is 2mA. Electron gun cathode current and G1, G2, G3 electrode voltages are all monitored by the microcontroller, once any abnormality is found, the G1 grid voltage is immediately turned off to ensure the safety of the system.

The cathode current adopts a constant current control circuit; the generation of G1, G2 and G3 voltage directly selects a controllable high-voltage voltage module, which simplifies the design of the entire system.

2) Scan control circuit design

The scanning control circuit is the key circuit of the whole VCSEL laser source. The block diagram of the control circuit is shown in Figure 2. In order to ensure that the electron beam velocity and incident angle are the same when the electron beam bombards each point on the surface of the VCSEL chip, and to ensure that the output laser intensity is uniform, it is necessary to control the electron beam scanning process.

As shown in Figure 2, the CPU is the core of the scanning control circuit. The CPU generates line and field synchronization pulse signals through the dual-port data memory RAM chip, and provides them to the TDA4857 deflection control integrated chip. Through the data interface, the CPU can control the TDA4857 chip to generate line and field scanning signal waveforms and line and field correction signal waveforms.

Due to the different deflection angles of the electron beams, the distances of the electron beam tracks are different. Theoretically, it is also required that the electron beams can be converged (focused) on the surface of the VCSEL chip, and the circuit is effectively compensated and adjusted through the dynamic focusing coil;

Although the deflection angle of the electron beam is the same (the angular velocity is the same), the linear velocity of each point on the surface of the VCSEL will be different due to the different radius and distance of the electron beam. The circuit is corrected by superimposing the current compensation signal in the row and field coils.

At the end of the single-line scan, when the line-feed scan is performed, the grid voltage of the electron gun G1 is controlled by the sequential circuit to realize the blanking of the electron beam.

In the whole circuit realization, the double damping line scanning output circuit is the core circuit, its main feature is to generate high-frequency and high-current scanning signals to drive the inductive load of the deflection coil, and the working principle of the circuit is the same as that of CRT products. The circuit design used in this system is shown in Figure 3.

In Fig. 3, L1 is the horizontal scanning coil as a load, D301 and D302 are damping diodes, and the horizontal scanning control signal controls the resonance process of L1 and the damping loop capacitance through Q301; the horizontal scanning compensation signal changes the horizontal deflection coil current loop through the Q303 branch circuit The purpose of compensation is to obtain the current; the PWM control signal of the power supply voltage can control the working voltage of the double damping line scanning loop, realize the control of the current amplitude of the deflection yoke, and change the line scanning range.

Results and discussion

Using the electron gun and VCSEL chip of the present invention, and based on the self-designed electronic control system, the VCSEL chip is successfully bombarded by the electron beam to produce a 630nm laser light source.

Claims (10)

1. A laser source system based on VCSEL technology, characterized in that, comprising: Electron gun and VCSEL chip package, including electron gun and VCSEL chip; The focusing coil is installed outside the electron gun and the VCSEL chip package, and is used to refocus the electron beam in the electron gun; The deflection coil is installed outside the electron gun and the VCSEL chip package, and is used to control the trajectory of the electron beam in the electron gun and control the incident orientation of the electron beam on the surface of the VCSEL chip; A microcontroller, connected with the electron gun, is used to control the starting and operation control of the electron gun; The scanning control unit is connected with the focus coil and the deflection coil respectively, and is used to drive the focus coil and the deflection coil; The central processing unit CPU is connected with the micro-controller and the scanning control unit respectively, and is used for the operation monitoring of the whole system; The man-machine interface is connected with the CPU, the operating parameters are set through the keyboard, and the operating parameters are recorded in real time. 2. A kind of laser source system based on VCSEL technology according to claim 1, it is characterized in that, described electron gun is a three-stage type intersection gun, comprises the cathode of electron emission, G1 grid, G2 accelerator and G3 electron focus pole. 3. A kind of laser source system based on VCSEL technology according to claim 1, characterized in that a thermally conductive substrate is bonded to the bottom of the VCSEL chip. 4. A kind of laser source system based on VCSEL technology according to claim 3, is characterized in that, also comprises the VCSEL semiconductor temperature control circuit that is connected with CPU, substrate respectively, is used for realizing the control of VCSEL chip temperature. 5. The laser source system based on VCSEL technology according to claim 1, further comprising output driving and amplifying circuits respectively connected to the scanning control unit, the focusing coil and the deflection coil. 6. A kind of laser source system based on VCSEL technology according to claim 1, is characterized in that, also comprises focus and deflection coil current detection circuit, this focus and deflection coil current detection circuit are connected with CPU, focus coil and deflection coil respectively connect. 7. A kind of laser source system based on VCSEL technology according to claim 5, it is characterized in that, described focus coil comprises static focus coil and dynamic focus coil, and described deflection coil comprises line deflection coil and field deflection coil , the scanning control unit includes: The static focus coil power supply is connected to the CPU and the static focus coil respectively; Scanning control circuit, connected with CPU; The field deflection coil driving circuit is connected with the scanning control circuit and the field deflection coil respectively; The horizontal deflection coil driving circuit is connected with the scanning control circuit and the horizontal deflection coil respectively; The dynamic focus coil driving circuit is connected with the line deflection coil and the amplification circuit respectively, wherein the amplification circuit is connected with the dynamic focus coil. 8. A kind of laser source system based on VCSEL technology according to claim 7, it is characterized in that, described field deflection coil drive circuit comprises and connects first pre-excitation circuit, power output circuit in sequence, and described first pre-excitation circuit The excitation circuit is connected with the scan control circuit, and the power output circuit is connected with the field deflection coil. 9. A kind of laser source system based on VCSEL technology according to claim 7, it is characterized in that, described line deflection coil drive circuit comprises the second pre-excitation circuit, line scan output circuit, sequential circuit and electron gun electron beam elimination Hidden circuit, the scanning control circuit is respectively connected with the second pre-excitation circuit, the row scanning output circuit and the sequential circuit, and the described row scanning output circuit is respectively connected with the second pre-excitation circuit and the horizontal deflection coil, and the row scanning output circuit is respectively connected with the second pre-excitation circuit and the horizontal deflection coil. The deflection coil and the timing circuit are respectively connected with the electron beam blanking circuit of the electron gun. 10. A kind of laser source system based on VCSEL technology according to claim 9, it is characterized in that, described dynamic focus coil driving circuit comprises line deflection coil scanning waveform sampling circuit, dynamic correction signal generation circuit connected in sequence, so The scanning waveform sampling circuit of the horizontal deflection coil is connected with the horizontal deflection coil, and the dynamic correction signal generation circuit is connected with the amplifying circuit.