In the vast sky of laser technology, nanosecond lasers have become the "precision surgical knives" in industrial manufacturing, medical research and other fields due to their unique pulse characteristics, efficient energy conversion and wide application scenarios.
The working principle of nanosecond laser
Nanosecond lasers generate optical amplification through the principle of stimulated radiation, with pulse widths in the nanosecond range (10 ⁻⁹ seconds), between continuous lasers and ultra short pulse lasers. Its working principle can be divided into three steps:
1. Pump excitation: Pump gain media (such as Nd:) through semiconductor diodes or xenon lamps YAG、 Fiber optic) to reverse the number of particles;
2. Resonant amplification: Photons oscillate back and forth within an optical resonant cavity, and are amplified by a gain medium to form high-energy pulses;
3. Pulse output: Q-switch or acousto-optic modulator precisely controls the pulse duration and repetition frequency to achieve instantaneous energy release.
The technological advantage lies in the fact that nanosecond level pulses can avoid the thermal accumulation effect of continuous lasers, are easier to maintain than picosecond/femtosecond lasers, have lower costs, and are suitable for large-scale industrial applications.
The synergy of wavelength, frequency, and power in nanosecond lasers
1. Wavelength range: covering the ultraviolet (355nm), visible light (532nm), and near-infrared (1064nm) bands. Short wavelength ultraviolet lasers are suitable for fine processing of transparent materials such as glass and ceramics; Long wavelength infrared lasers have higher absorption rates for materials such as metals and plastics.
2. Repetition frequency: adjustable from 1kHz to 500kHz, high frequency is suitable for fast marking and thin plate cutting, low frequency is suitable for deep carving or drilling of thick materials.
3. Power characteristics:
Single pulse energy: up to several millijoules (mJ), peak power exceeding one hundred kilowatts, instantaneous vaporization of materials;
Average power: By superimposing multiple pulses, continuous output of tens of watts can be achieved, balancing efficiency and accuracy.
The 5 core characteristics of nanosecond lasers
1. The heat affected zone is extremely small: the nanosecond pulse has a short duration of action, and the temperature rise in the surrounding area of the material is controllable, avoiding cracks and deformation;
2. Excellent beam quality: using a laser mode with M ²<1.2, the focused spot diameter can be compressed to the micrometer level;
3. Strong stability: The fully digital control system ensures power fluctuations are less than 3% and supports 24-hour continuous production;
4. Easy to integrate: modular design compatible with robots, mirrors, and assembly lines, achieving flexible manufacturing;
5. High cost-effectiveness: Compared to ultra short pulse lasers, equipment investment is reduced by more than 40%, and maintenance costs are lower.
Application areas: Deep empowerment from industry to scientific research
1. Industrial manufacturing
Precision machining: automotive parts (such as engine cylinder micro hole machining), consumer electronics (mobile phone camera module cutting), hardware molds (complex pattern carving);
Surface treatment: metal cleaning, coating removal, replacing traditional chemical etching, no environmental pollution.
2. Medical Aesthetics
Treatment of pigmentary lesions: removal of freckles and tattoos, utilizing the principle of selective absorption of laser and pigments;
Skin rejuvenation: Stimulate collagen regeneration through laser and biological tissue thermal interaction.
3. Research and 3D Printing
Spectral analysis: A highly stable laser source provides a light source for Raman spectroscopy and fluorescence detection;
Additive manufacturing: Metal powder sintering, ceramic 3D printing, achieving integrated molding of complex structures.
4. National Defense and Security
Laser ranging: High repetition rate lasers are used for drone obstacle avoidance and terrain mapping;
Optoelectronic countermeasure: Specific wavelength lasers interfere with enemy optoelectronic equipment.
