A multi-mode laser modulation switching circuit, method and laser generating device

Abstract

The application discloses a multi-mode laser modulating switching circuit, method and laser generating device. The multi-mode laser modulating switching circuit is constructed by means of a first logic gate unit with at least four gating modes and a second logic gate unit with at least two gating modes, which allows to realize the switching function of five laser light-emitting modes including internal trigger narrow pulse, external trigger narrow pulse and the like by simply controlling the channel selection of the logic gate unit and the trigger signal of the input, meanwhile, the consistent narrow pulse signal pulse width under the internal and external trigger modes can be ensured without adjusting the narrow pulse width of the internal trigger signal, and the minimum pulse width requirement of the internal trigger signal generation source under the internal trigger narrow pulse light-emitting mode can be avoided.

Description

Technical Field

[0001] This invention relates to the field of laser technology, specifically to a multi-mode laser modulation switching circuit and method, and a laser generating device based thereon. Background Technology

[0002] In laser applications, it is often necessary to control and switch the laser emission mode to meet different technical requirements. Figure 1 This paper illustrates a laser emission mode switching scheme in the prior art, wherein the circuitry for implementing mode switching may include a comparator and a 2*1 channel logic chip. (The last sentence appears to be incomplete and possibly refers to a different approach.) Figure 1 In the circuit structure, when the internal trigger mode is selected, the comparator's output Q is set to logic 0. Therefore, the 2*1 channel logic chip selects the channel D0 input via the channel selection pin. This means the output of the 2*1 channel logic chip is determined by the input of channel D0. Thus, by adjusting the pulse width of the internal trigger signal in input channel D0, the 2*1 channel logic chip can output a laser drive signal with a corresponding pulse width. When the external trigger mode is selected, because the distances between the comparator's output Q# and the pin of channel D1 of the 2*1 channel logic chip are different from the distances between the comparator's output Q and the channel selection pin of the 2*1 channel logic chip, the 2*1 channel logic chip generates and outputs a narrow pulse with a fixed pulse width as the laser drive signal by utilizing the time difference between the time the comparator output signal arrives at the channel selection pin and the pin of channel D1.

[0003] However, current technologies can only switch between three light emission modes: externally triggered narrow pulse, internally triggered narrow pulse, and internally triggered wide pulse. Furthermore, because the external and internal trigger signals reach the 2*1 channel logic chip via different paths (i.e., different generation methods), the width of the internally triggered narrow pulse needs to be adjusted to match the pulse width of the externally triggered narrow pulse generated by the difference in line length. Only then can the same narrow pulse drive signal be obtained in both trigger modes. Therefore, in narrow pulse light emission modes with pulse widths within tens of picoseconds, the requirements for the source generating the internally triggered narrow pulse signal are relatively high; it must be able to emit a drive electrical signal smaller than the pulse width of the narrow pulse light source. Summary of the Invention

[0004] To address the aforementioned deficiencies in the prior art, this invention discloses a multi-mode laser modulation and switching circuit, method, and laser generating device. Specifically, a multi-mode laser modulation and switching circuit is constructed using a first logic gate unit with at least four gating modes and a second logic gate unit with at least two gating modes. This circuit allows for the simple switching of five laser emission modes, including internally triggered narrow pulses and externally triggered narrow pulses, by controlling the channel selection and input trigger signals of the logic gate units. Furthermore, it ensures consistent narrow pulse widths in both internal and external trigger modes without requiring adjustments to the narrow pulse width of the internal trigger signal, and avoids the minimum pulse width requirement for the internal trigger signal generator in the internally triggered narrow pulse emission mode.

[0005] Specifically, the first aspect of the present invention relates to a multi-mode laser modulation switching circuit, which includes at least a first logic gate unit and a second logic gate unit.

[0006] The first logic gate unit includes at least first and second input channels and first and second output channels, and is configured to be able to switch between first, second, third and fourth strobe modes based at least on the first channel selection signal;

[0007] The second logic gate unit includes at least third and fourth input channels and a third output channel, and is configured to switch between a fifth and a sixth strobe mode based at least on a second channel selection signal; wherein,

[0008] The first input channel is configured to receive an internal trigger signal;

[0009] The second input channel is configured to receive an external trigger signal;

[0010] The first output channel is configured to be connected to the third input channel via the first transmission line;

[0011] The second output channel is configured to provide a second channel selection signal to the second logic gate unit via the second transmission line;

[0012] The third output channel is configured to output laser drive signals;

[0013] The first gating mode is set such that the output of the first output channel is referenced to the input of the first input channel, and the output of the second output channel is referenced to the input of the first input channel;

[0014] The second gating mode is set such that the output of the first output channel references the input of the second input channel, and the output of the second output channel references the input of the second input channel;

[0015] The third gating mode is set such that the output of the first output channel references the input of the first input channel, and the output of the second output channel references the input of the second input channel;

[0016] The fourth gating mode is set such that the output of the first output channel references the input of the second input channel, and the output of the second output channel references the input of the first input channel;

[0017] The fifth gating mode is set to make the output of the third output channel reference the input of the third input channel;

[0018] The sixth strobe mode is configured to make the output of the third output channel reference the input of the fourth input channel; and,

[0019] The length L1 of the first transmission line is different from the length L2 of the second transmission line.

[0020] Furthermore, the first logic gate unit also includes first and second channel selection pins for receiving a first channel selection signal, and the second logic gate unit also includes a third channel selection pin for receiving a second channel selection signal.

[0021] Preferably, the first logic gate unit includes a 2*2 channel logic chip, and / or the second logic gate unit includes a 2*1 channel logic chip.

[0022] Furthermore, the fourth input channel is set to a constant high or low level.

[0023] Furthermore, the multi-mode laser modulation switching circuit of the present invention can be configured to switch between at least two emission modes;

[0024] The emission modes include internally triggered narrow pulse, internally triggered wide pulse, externally triggered narrow pulse, externally triggered wide pulse, and continuous light emission mode.

[0025] Furthermore, the difference between the lengths L2 and L1 is determined by the pulse width of the narrow pulse.

[0026] Furthermore, in the internally triggered narrow pulse light emission mode, the first logic gate unit operates in the first gating mode, and the internal trigger signal is set to have a 50% duty cycle.

[0027] In the externally triggered narrow pulse light emission mode, the first logic gate unit operates in the second gating mode, and the external trigger signal is set to have a 50% duty cycle;

[0028] In the internally triggered wide-pulse light emission mode, the first logic gate unit operates in the third gating mode, the second logic gate unit operates in the fifth gating mode, and the internal trigger signal is set to have the desired pulse width.

[0029] In the externally triggered wide-pulse light emission mode, the first logic gate unit operates in the fourth gating mode, the second logic gate unit operates in the fifth gating mode, and the external trigger signal is set to have the desired pulse width.

[0030] In continuous light emission mode, the first logic gate unit operates in the third gating mode, the second logic gate unit operates in the fifth gating mode, and the internal trigger signal is set to have a constant high level or low level; or, the first logic gate unit operates in the fourth gating mode, the second logic gate unit operates in the fifth gating mode, and the external trigger signal is set to have a constant high level or low level.

[0031] Preferably, the internal trigger signal with a 50% duty cycle is a square wave signal, and / or the external trigger signal with a 50% duty cycle is a square wave signal.

[0032] A second aspect of the present invention relates to a multi-mode laser modulation switching method for switching between at least two emission modes by means of the aforementioned multi-mode laser modulation switching circuit.

[0033] Furthermore, the light emission mode is switched by controlling the input signal and gating mode of the first logic gate unit;

[0034] The emission modes include internally triggered narrow pulse, internally triggered wide pulse, externally triggered narrow pulse, externally triggered wide pulse, and continuous light emission mode.

[0035] A third aspect of the invention relates to a laser generating apparatus comprising a laser and the aforementioned multimode laser modulation switching circuit, the multimode laser modulation switching circuit being configured to provide a laser driving signal to the laser. Attached Figure Description

[0036] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This illustrates a laser emission mode switching scheme in the prior art;

[0039] Figure 2 An example of a multi-mode laser modulation switching circuit according to the present invention is shown;

[0040] Figure 3 The generation process of the narrow pulse signal according to the present invention is illustrated schematically. Detailed Implementation

[0041] In the following description, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example in order to fully convey the spirit of the invention to those skilled in the art. Therefore, the invention is not limited to the embodiments disclosed herein.

[0042] Figure 2 An example of a multimode laser modulation switching circuit according to the present invention is shown.

[0043] According to the present invention, the multi-mode laser modulation switching circuit may include a first logic gate unit and a second logic gate unit.

[0044] The first logic gate unit has at least two input channels and two output channels, and the connection between the input channels and the output channels can be controlled by the channel selection signal.

[0045] The two input channels are designated as the first and second input channels, and the two output channels are designated as the first and second output channels. Using the first channel selection signal for the first logic gate unit, the following four gating modes can be switched between the two input channels and the two output channels:

[0046] First gating mode: The output of the first output channel is referenced to the input of the first input channel, and the output of the second output channel is referenced to the input of the first input channel;

[0047] Second gating mode: The output of the first output channel is referenced to the input of the second input channel, and the output of the second output channel is referenced to the input of the second input channel;

[0048] Third gating mode: The output of the first output channel is referenced to the input of the first input channel, and the output of the second output channel is referenced to the input of the second input channel;

[0049] Fourth gating mode: The output of the first output channel is referenced to the input of the second input channel, and the output of the second output channel is referenced to the input of the first input channel.

[0050] The second logic gate unit has at least two input channels and one output channel, and the connection between the input channel and the output channel can also be controlled by the channel selection signal.

[0051] The two input channels in the second logic gate unit are designated as the third and fourth input channels, and the output channel is designated as the third output channel. Using the second channel selection signal for the second logic gate unit, the following two gating modes can be switched between these two input channels and one output channel:

[0052] Fifth strobe mode: The output of the third output channel is referenced to the input of the third input channel;

[0053] Sixth strobe mode: The output of the third output channel refers to the input of the fourth input channel.

[0054] See also Figure 2 In the multi-mode laser modulation switching circuit of the present invention, the first output channel of the first logic gate unit is connected to the third input channel of the second logic gate unit through a first transmission line. Simultaneously, the second output channel of the first logic gate unit provides a second channel selection signal to the second logic gate unit through a second transmission line to control the gating mode in the second logic gate unit. The length L1 of the first transmission line is different from the length L2 of the second transmission line, so that the time delay experienced by signals simultaneously output from the first logic gate unit reaching the second logic gate unit via different transmission lines is different. The input of the fourth input channel can be configured to be constantly low (or have its input pin grounded) or configured to be high.

[0055] Therefore, by inputting an internal trigger signal at the first input channel of the first logic gate unit, or an external trigger signal at the second input channel, and by using the first channel selection signal to control the gating mode between the first and second input channels and the first and second output channels in the first logic gate unit, different laser driving signals can be generated at the third output channel of the second logic gate unit to realize different emission modes such as internal trigger narrow pulse, internal trigger wide pulse, external trigger narrow pulse, external trigger wide pulse, and continuous light emission mode.

[0056] To better understand this invention, the following will be combined with Figure 2 The following example describes the working principle of the multimode laser modulation switching circuit of the present invention.

[0057] exist Figure 2In the example, the first logic gate unit is implemented using a 2x2 channel logic chip, and the second logic gate unit is implemented using a 2x1 channel logic chip. However, those skilled in the art will understand that logic gate units can also be implemented using other logic circuit structures, such as cross-point switches. Furthermore, even when logic chips are used to implement logic gate units, the logic chips used are not limited to 2x2 or 2x1 channels; they can be any multi-channel logic chip capable of providing the aforementioned gating mode selection function, such as 3x2, 2x3, 3x3, or 4x3 channels.

[0058] like Figure 2 As shown, the 2x2 channel logic chip includes a first input channel IN0, a second input channel IN1, a first output channel Q0, a second output channel Q1, and a first channel selection pin SEL0 and a second channel selection pin SEL1. The states of the first and second channel selection pins SEL0 and SEL1 are controlled by the two first channel selection signals, thus controlling the connectivity between the first and second input channels and the first and second output channels. That is, the high and low levels of pins SEL0 and SEL1 can be configured in four different ways using the first channel selection signals, thereby enabling switching between four selection modes and achieving four different output states in the 2x2 channel logic chip.

[0059] Table 1 provides an example of a truth table for input / output channel selection in a 2x2 channel logic chip:

[0060]

[0061] (Table 1)

[0062] As shown in Table 1, when both the first and second channel selection pins SEL0 and SEL1 are in a low-level state L, both the first output channel Q0 and the second output channel Q1 are selected and connected to the first input channel IN0. At this time, the output of the first output channel Q0 is referenced to the input of the first input channel IN0, and the output of the second output channel Q1 is referenced to the input of the first input channel IN0.

[0063] When the first channel selection pin SEL0 is low (L) and the second channel selection pin SEL1 is high (H), the first output channel Q0 is selected and connected to the first input channel IN0, and the second output channel Q1 is selected and connected to the second input channel IN1. At this time, the output of the first output channel Q0 is referenced to the input of the first input channel IN0, and the output of the second output channel Q1 is referenced to the input of the second input channel IN1.

[0064] When the first channel selection pin SEL0 is high (H) and the second channel selection pin SEL1 is low (L), the first output channel Q0 is selected and connected to the second input channel IN1, and the second output channel Q1 is selected and connected to the first input channel IN0. At this time, the output of the first output channel Q0 is referenced to the input of the second input channel IN1, and the output of the second output channel Q1 is referenced to the input of the first input channel IN0.

[0065] When both the first and second channel selection pins SEL0 and SEL1 are at a high level, the first and second output channels Q0 and Q1 are both selected and connected to the second input channel IN1. At this time, the output of the first output channel Q0 is referenced to the input of the second input channel IN1, and the output of the second output channel Q1 is referenced to the input of the second input channel IN1.

[0066] like Figure 2 As shown, the 2*1 channel logic chip used to implement the second logic gate unit includes a third input channel D0, a fourth input channel D1, a third output channel, and a third channel selection pin. By introducing a second channel selection signal at the third channel selection pin, the state of the third channel selection pin can be controlled, allowing selection of the connection between the third and fourth input channels and the third output channel. That is, by using the second channel selection signal to configure the high and low levels of the third channel selection pin, two different gating modes can be switched within the 2*1 channel logic chip, thereby achieving two different output states.

[0067] For example, when the third channel selection pin is in a low level state L, the third output channel is selected and connected to the third input channel D0. At this time, the output of the third output channel is referenced to the input of the third input channel D0.

[0068] When the third channel selection pin is in a high level state H, the third output channel is selected and connected to the fourth input channel D1. At this time, the output of the third output channel is referenced to the input of the fourth input channel D1.

[0069] exist Figure 2 In the example, the first input channel IN0 is configured to receive an internal trigger signal, and the second input channel IN1 is configured to receive an external trigger signal. The output of the first output channel Q0 reaches the third input channel D0 via the first transmission line, and the output of the second output channel Q1 reaches the third channel selection pin via the second transmission line. The input of the fourth input channel D1 is configured to be always low or to ground the input pin of the fourth input channel D1. The third output channel is used to output the laser drive signal. The length L1 of the first transmission line is set to be different from the length L2 of the second transmission line, for example, by creating a difference in line length during PCB routing.

[0070] In this invention, the signals input to each input channel and the signals output to each output channel are differential signals, such as... Figure 2 As shown.

[0071] According to the present invention, the length difference |L2-L1| between the first and second transmission lines can be determined based on the pulse width t of the narrow pulse used for the laser driving signal. Therefore, by means of a multi-mode laser modulation switching circuit, switching can be performed between five emission modes, namely, internal trigger narrow pulse, internal trigger wide pulse, external trigger narrow pulse, external trigger wide pulse, and continuous light emission mode, thereby obtaining the desired emission mode.

[0072] The following is combined with Figure 2 The example further illustrates the multi-mode laser modulation switching method according to the present invention.

[0073] By using the multi-mode laser modulation switching circuit of the present invention, switching control between at least two emission modes (e.g., internal trigger narrow pulse, internal trigger wide pulse, external trigger narrow pulse, external trigger wide pulse and continuous light emission mode) can be easily achieved by controlling the gating mode of the first and second logic gate units (e.g., 2*2 channel logic chip and 2*1 channel logic chip) and selecting the input (internal trigger signal or external trigger signal and signal parameters) for the first logic gate unit.

[0074] For example, in Figure 2 In the example, the states of the first and second channel selection pins SEL0 and SEL1 of the 2*2 channel logic chip can be controlled so that the outputs of the first and second output channels Q0 and Q1 are both referenced to the input of the first input channel IN0. At this time, by setting the internal trigger signal to a square wave signal with a 50% duty cycle, the third output channel of the 2*1 channel logic chip can output a laser drive signal with a pulse width t, thereby realizing the internally triggered narrow pulse emission mode.

[0075] Figure 3 An exemplary illustration shows the process of generating narrow pulses in an internally triggered narrow pulse emission mode.

[0076] like Figure 3 As shown, when the first and second channel selection pins SEL0 and SEL1 are both in a low-level state by means of two first channel selection signals, the first and second output channels are both connected to the first input channel IN0, and the outputs of the first and second output channels Q0 and Q1 are both referenced to the input of the first input channel IN0, thereby switching the multi-mode laser modulation switching circuit to the internally triggered narrow pulse emission mode.

[0077] At this time, an internal trigger signal can be selected as the input, and a square wave differential signal with a duty cycle of 50% can be input at the first input channel IN0, thereby outputting a square wave differential signal with a duty cycle of 50% at the first and second output channels Q0 and Q1 respectively.

[0078] Since the first transmission line L1 is shorter than the second transmission line L2, the differential signal output from the first output channel Q0 will reach the third input channel first. At this time, the third channel selection pin is in a low-level state, and the third input channel D0 in the 2*1 channel logic chip is connected to the third output channel, so the third output channel will output a high-level signal accordingly.

[0079] When the differential signal output by the second output channel Q1 reaches the third channel selection pin after a time delay t (determined by the difference between L2 and L1), the third channel selection pin changes from a low level to a high level. The fourth input channel, which is always low or grounded, is connected to the third output channel, and the signal output by the third output channel changes from a high level to a low level accordingly, thereby realizing a narrow pulse signal with a pulse width of t driven by the internal trigger signal.

[0080] Similarly, the states of the first and second channel selection pins SEL0 and SEL1 of the 2*2 channel logic chip can be controlled (e.g., both are set to a high level) so that the output of the first output channel Q0 references the input of the second input channel IN1, and the output of the second output channel Q1 references the input of the second input channel IN1. At this time, selecting an external trigger signal as input and setting it to a square wave signal with a 50% duty cycle will cause the third output channel to output a laser drive signal with a pulse width t, thereby realizing an externally triggered narrow pulse emission mode.

[0081] It can be noted that in the externally triggered narrow pulse emission mode, the narrow pulse is also achieved using the first and second transmission lines with a line length difference, and its pulse width is determined by the same line length difference. Therefore, in both internal and external trigger modes, the narrow pulse is generated in the same way, which effectively ensures the stability and consistency of the pulse width in the narrow pulse mode, and eliminates the need for a minimum pulse width requirement for the internal trigger signal source.

[0082] Similarly, the states of the first and second channel selection pins SEL0 and SEL1 (e.g., SEL0 is low and SEL1 is high) and the state of the third channel selection pin (low) can be controlled so that the output of the first output channel Q0 references the input of the first input channel IN0, the output of the second output channel Q1 references the input of the second input channel IN1, and the output of the third output channel references the input of the third input channel. Since the output of the third output channel is always determined by the input of the first input channel IN0, the shape (e.g., square wave) and pulse width (e.g., the required wide pulse width for the laser drive signal) of the internal trigger signal can be controlled, resulting in a consistent laser drive signal output from the third output channel, thereby achieving an internally triggered wide-pulse emission mode.

[0083] Furthermore, the states of the first and second channel selection pins SEL0 and SEL1 (e.g., SEL0 is high and SEL1 is low) and the state of the third channel selection pin (low) can be controlled so that the output of the first output channel Q0 references the input of the second input channel IN1, the output of the second output channel Q1 references the input of the first input channel IN0, and the output of the third output channel references the input of the third input channel. Since the output of the third output channel is always determined by the input of the second input channel IN1, the shape (e.g., square wave) and pulse width (e.g., the required wide pulse width for the laser drive signal) of the external trigger signal can be controlled, resulting in a consistent laser drive signal output by the third output channel, thereby achieving an externally triggered wide pulse emission mode.

[0084] Furthermore, the states of the first and second channel selection pins SEL0 and SEL1, as well as the state of the third channel selection pin, can be controlled so that the output of the first output channel Q0 references the input of the first input channel IN0, the output of the second output channel Q1 references the input of the second input channel IN1, and the output of the third output channel references the input of the third input channel. At this time, by maintaining a constant high (or low) level on the internal trigger signal, the third output channel outputs a continuous laser drive signal, thereby achieving a continuous light emission mode.

[0085] Alternatively, the states of the first and second channel selection pins SEL0 and SEL1, as well as the state of the third channel selection pin, can be controlled so that the output of the first output channel Q0 references the input of the second input channel IN1, the output of the second output channel Q1 references the input of the first input channel IN0, and the output of the third output channel references the input of the third input channel. In this case, by maintaining a constant high (or low) level on the external trigger signal, the third output channel outputs a continuous laser drive signal, thereby achieving a continuous light emission mode.

[0086] Table 2 presents an example of the multi-mode laser modulation switching configuration table of the present invention, wherein "L" represents the low level state of the channel selection pin and the logic 0 state of the input pin, "H" represents the high level state of the channel selection pin and the logic 1 state of the input pin, and "NC" represents that there are no requirements for the logic state of the input pin.

[0087]

[0088] (Table 2)

[0089] In summary, this invention utilizes a first logic gate unit with at least four gating modes and a second logic gate unit with at least two gating modes to construct a multi-mode laser modulation and switching circuit. By leveraging the special signal transmission relationship between the first and second logic gate units, and by configuring specific line length differences on the signal transmission lines from different output pins in the first logic gate unit to the second logic gate unit, it is possible to easily switch between five laser emission modes, including internally triggered narrow pulses and externally triggered narrow pulses, by controlling the channel selection and input trigger signals of the logic gate units. Simultaneously, the internal and external trigger signals arrive at the second logic gate unit along the same path, thus allowing the narrow pulse laser drive signals in both internal and external trigger modes to be generated in the same manner, eliminating the need to adjust the narrow pulse width of the internal trigger signal to ensure consistent pulse widths in both modes. Furthermore, since the narrow pulses are achieved through line length differences in the same transmission lines, the minimum pulse width requirement for the internal trigger signal generation source in the internally triggered narrow pulse emission mode can be avoided; only a signal with a 50% duty cycle at the corresponding emission frequency needs to be output.

[0090] Furthermore, the present invention also discloses a laser generating device, which includes a laser and the aforementioned multi-mode laser modulation and switching circuit. Therefore, by providing inputs to the multi-mode laser modulation and switching circuit from the internal trigger signal generation source and the external trigger signal generation source, the switching between multiple emission modes can be achieved through channel selection control of the logic chip in the multi-mode laser modulation and switching circuit.

[0091] Although the present invention has been described above with reference to the accompanying drawings and specific embodiments, those skilled in the art will readily recognize that the above embodiments are merely exemplary and used to illustrate the principles of the present invention. They do not limit the scope of the present invention. Those skilled in the art can make various combinations, modifications and equivalent substitutions to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. A multi-mode laser modulation switching circuit, comprising at least a first logic gate unit and a second logic gate unit; The first logic gate unit includes at least first and second input channels and first and second output channels, and is configured to be able to switch between first, second, third and fourth strobe modes based at least on the first channel selection signal; The second logic gate unit includes at least third and fourth input channels and a third output channel, and is configured to switch between a fifth and a sixth strobe mode based at least on a second channel selection signal; wherein, The first input channel is configured to receive an internal trigger signal; The second input channel is configured to receive an external trigger signal; The first output channel is configured to be connected to the third input channel via the first transmission line; The second output channel is configured to provide a second channel selection signal to the second logic gate unit via the second transmission line; The third output channel is configured to output laser drive signals; The first gating mode is set such that the output of the first output channel is referenced to the input of the first input channel, and the output of the second output channel is referenced to the input of the first input channel; The second gating mode is set such that the output of the first output channel references the input of the second input channel, and the output of the second output channel references the input of the second input channel; The third gating mode is set such that the output of the first output channel references the input of the first input channel, and the output of the second output channel references the input of the second input channel; The fourth gating mode is set such that the output of the first output channel references the input of the second input channel, and the output of the second output channel references the input of the first input channel; The fifth gating mode is set to make the output of the third output channel reference the input of the third input channel; The sixth strobe mode is set to make the output of the third output channel reference the input of the fourth input channel; and, The length L1 of the first transmission line is different from the length L2 of the second transmission line.

2. The multi-mode laser modulation switching circuit as described in claim 1, wherein, The first logic gate unit further includes first and second channel selection pins for receiving a first channel selection signal, and the second logic gate unit further includes a third channel selection pin for receiving a second channel selection signal.

3. The multi-mode laser modulation switching circuit as described in claim 1, wherein, The first logic gate unit includes a 2*2 channel logic chip, and / or the second logic gate unit includes a 2*1 channel logic chip.

4. The multi-mode laser modulation switching circuit as described in claim 1, wherein, The fourth input channel is set to a constant high or low level.

5. The multi-mode laser modulation switching circuit as described in any one of claims 1-4, wherein it is configured to switch between at least two emission modes; in, The emission modes include internally triggered narrow pulse, internally triggered wide pulse, externally triggered narrow pulse, externally triggered wide pulse, and continuous light emission mode.

6. The multi-mode laser modulation switching circuit as described in claim 5, wherein, The difference between the lengths L2 and L1 is determined by the pulse width of the narrow pulse.

7. The multi-mode laser modulation switching circuit as described in claim 5, wherein: In the internally triggered narrow pulse light emission mode, the first logic gate unit operates in the first gating mode, and the internal trigger signal is set to have a 50% duty cycle. In the externally triggered narrow pulse light emission mode, the first logic gate unit operates in the second gating mode, and the external trigger signal is set to have a 50% duty cycle; In the internally triggered wide-pulse light emission mode, the first logic gate unit operates in the third gating mode, the second logic gate unit operates in the fifth gating mode, and the internal trigger signal is set to have the desired pulse width. In the externally triggered wide-pulse light emission mode, the first logic gate unit operates in the fourth gating mode, the second logic gate unit operates in the fifth gating mode, and the external trigger signal is set to have the desired pulse width. In continuous light emission mode, the first logic gate unit operates in the third gating mode, the second logic gate unit operates in the fifth gating mode, and the internal trigger signal is set to have a constant high level or low level; or, the first logic gate unit operates in the fourth gating mode, the second logic gate unit operates in the fifth gating mode, and the external trigger signal is set to have a constant high level or low level.

8. The multi-mode laser modulation switching circuit as described in claim 7, wherein, An internal trigger signal with a 50% duty cycle is a square wave signal, and / or an external trigger signal with a 50% duty cycle is a square wave signal.

9. A multi-mode laser modulation switching method for switching between at least two emission modes using a multi-mode laser modulation switching circuit as described in any one of claims 1-8.

10. The multi-mode laser modulation switching method as described in claim 9, wherein, The light emission mode is switched by controlling the input signal and gating mode of the first logic gate unit; The emission modes include internally triggered narrow pulse, internally triggered wide pulse, externally triggered narrow pulse, externally triggered wide pulse, and continuous light emission mode.

11. A laser generating apparatus comprising a laser and a multimode laser modulation switching circuit as described in any one of claims 1-8, the multimode laser modulation switching circuit being configured to provide a laser driving signal to the laser.

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