US 2026/0088587 A1Published application

Laser Current Control Method, Apparatus, and Laser Device for Suppressing Laser Relaxation Oscillations

AssigneesSuzhou Menovex Photonics Technology Co., Ltd, Menovex Medical Technology (Shenzhen) Co., Ltd

InventorsZuyong Huang, Encai Ji, Yixiang Dai, Wenqiang Bao, Qiguo Yang, Jinzi Bi, Ke Zeng

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Abstract

The present disclosure provides a laser current control method for suppressing laser relaxation oscillations, relating to the field of laser control technologies. The method comprising: controlling a current signal with a preset waveform to be input into a laser drive circuit; the preset waveform includes a first step and a second step, where the amplitude of the first step is less than that of the second step, and the current signal of the first step triggers a laser relaxation oscillation waveform whose amplitude is less than a safety threshold; and adjusting the amplitude of the second step based on a relationship between the average laser output power and the drive current. According to the embodiments of the present disclosure, a small-step current waveform is designed to effectively suppress damage to optical components in the optical path caused by laser relaxation oscillations. The reduced pulse distortion ensures that the threshold current corresponding to different pulse frequencies exhibits linearity under the same duty cycle, eliminating the need to record threshold currents and corresponding linear equations for each duty cycle. This allows the output current to be more precisely and accurately adjusted to achieve a desired terminal average power.

Claims5

Dependent claims

A laser current control method for suppressing laser relaxation oscillations, comprising:

controlling a current signal with a preset waveform to be input to a laser drive circuit;
wherein the preset waveform comprises a first step and a second step, an amplitude of the first step being smaller than an amplitude of the second step, and a laser relaxation oscillation waveform triggered by the current signal of the first step having an amplitude less than a safety threshold;
adjusting the amplitude of the second step based on a relationship between average laser output power and drive current;
wherein the current signal of the second step is processed by the laser drive circuit to obtain the drive current;
and the relationship between the average laser output power and the drive current is determined by a peak power corresponding to the first step, a duty cycle corresponding to the first step, a maximum drive current, a threshold current, a peak power corresponding to the maximum drive current, and a duty cycle corresponding to the second step, wherein the relationship between the average laser output power and the drive current signal is as follows:
P
out
=
P
p
⁢
_
⁢
It
⁢
0
*
(
t
0
*
f
)
+
[
(
I
out
-
I
th
)
/
(
I
max
-
I
th
)
]
*
(
P
pmax
*
D
)
wherein Pout is the average laser output power;
Pp_It0 is the peak power corresponding to the first step;
t0*f is the duty cycle corresponding to the first step;
t0 is the width of the first step;
Iout is the drive current;
Imax is the maximum drive current;
Ith is the threshold current;
Ppmax is the peak laser power corresponding to the maximum drive current;
and D is the duty cycle corresponding to the second step,
wherein the threshold current is linearly and positively correlated with the laser pulse frequency,
wherein the relationship between the threshold current and the laser pulse frequency is as follows:
Ith=Af+B
wherein f is the laser pulse frequency, and A and B are coefficients.

58 more elements

A laser current control apparatus for suppressing laser relaxation oscillations, comprising:

a waveform output module configured to control a current signal with a preset waveform to be input to a laser drive circuit;
wherein the preset waveform comprises a first step and a second step, the amplitude of the first step being smaller than an amplitude of the second step, and a laser relaxation oscillation waveform triggered by the current signal of the first step having an amplitude less than a safety threshold;
a regulation module configured to adjust the amplitude of the second step based on the relationship between average laser output power and the drive current;
wherein the current signal of the second step is processed by the laser drive circuit to obtain the drive current;
and
wherein the relationship between the average laser output power and the drive current is determined by a peak power corresponding to the first step, a duty cycle corresponding to the first step, the maximum drive current, the threshold current, the peak laser power corresponding to the maximum drive current, and the duty cycle corresponding to the second step,
wherein the relationship between the average laser output power and the drive current signal is as follows:
P
out
=
P
p
⁢
_
⁢
It
⁢
0
*
(
t
0
*
f
)
+
[
(
I
out
-
I
th
)
/
(
I
max
-
I
th
)
]
*
(
P
pmax
*
D
)
wherein Pout is the average laser output power;
Pp_It0 is the peak power corresponding to the first step;
t0*f is the duty cycle corresponding to the first step;
t0 is the width of the first step;
Lout is the drive current;
Imax is the maximum drive current;
In is the threshold current;
Ppmax is the peak laser power corresponding to the maximum drive current;
and D is the duty cycle corresponding to the second step,
wherein the threshold current is linearly and positively correlated with the laser pulse frequency,
wherein the relationship between the threshold current and the laser pulse frequency is as follows:
I
th
=
Af
+
B
wherein f is the laser pulse frequency, and A and B are coefficients.

65 more elements

Dependencies are inferred from the claim text.

Facts

Application: 19/196,739Filed 2 May 2025
Priority: CN 202410703660.X3 Jun 2024
Published: 26 Mar 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01S 5/0428
Electrical excitation ; Circuits therefor: for applying pulses to the laser
H01S 5/0617
Arrangements for controlling the laser output parameters, e.g. by operating on the active medium: using memorised or pre-programmed laser…
H01S 5/0427
Electrical excitation ; Circuits therefor: for applying modulation to the laser
H01S 5/06216
In single-section lasers: pulse modulation or generation