What is 1064nm Laser

 A 1064nm laser is a type of infrared laser that can be generated by a diode or a diode-pumped solid state (DPSS) device. It can have various applications in science, medicine, industry and military. For example, it can be used for:

• Laser-induced breakdown spectroscopy (LIBS), a technique that analyzes the elemental composition of a material by creating a plasma with a laser pulse and measuring the emitted light.
• Laser hair removal, a cosmetic procedure that destroys the hair follicles by heating them with a laser beam.
• Treating vascular skin lesions, such as spider veins, port-wine stains and hemangiomas, by selectively damaging the blood vessels with a 532nm green light that is obtained by frequency-doubling a 1064nm laser.
• Laser seeding, a method of injecting a low-power laser beam into a high-power amplifier to improve the beam quality and stability.

Laser-induced thermotherapy, a minimally invasive treatment that ablates benign or malignant tumors by heating them with a laser beam.

This wavelength is important because it has several advantages, such as:

• It can be easily converted to other wavelengths by nonlinear optical processes, such as frequency-doubling, tripling or mixing.
• It can be efficiently coupled into optical fibers, which enables flexible delivery and remote operation of the laser.
• It can penetrate deeper into biological tissues than visible or ultraviolet light, which makes it suitable for medical applications.
• It can interact strongly with many materials, such as metals, ceramics and plastics, which makes it useful for material processing and analysis.

There are different ways to produce 1064 nm lasers, which are infrared lasers that can reach deeper layers of skin tissue than other types of lasers. Some of the methods are:

• Using diode-pumped solid-state (DPSS) lasers that use a crystal of neodymium-doped yttrium aluminium garnet (Nd:YAG) as the laser medium. These lasers can be operated in continuous wave (CW) or Q-switched mode, which produces short pulses of high-intensity light.
• Using laser diodes that emit 1064 nm light directly or through a volume Bragg grating (VBG) that stabilizes the wavelength. These diodes can have free space or fiber coupled outputs and can be single-mode or multi-mode.
• Using fiber lasers that use a doped optical fiber as the gain medium and a pump source such as a laser diode. These lasers can be pulsed or CW and have high beam quality and efficiency.

People may still use 808nm + NdYAG for producing 1064nm laser because this method has some advantages over using a direct 1064nm diode laser, such as:

• Higher beam quality: A diode-pumped solid state (DPSS) laser using NdYAG as the gain medium can produce a high-quality beam with low divergence and high spatial resolution, which is suitable for applications that require precise focusing or collimation.
• Higher peak power: A DPSS laser using NdYAG can produce high peak power pulses with short duration and high repetition rate, which is suitable for applications that require high intensity or nonlinear frequency conversion.
• Wavelength versatility: A DPSS laser using NdYAG can produce different wavelengths by using nonlinear optical processes, such as frequency-doubling, tripling or mixing. For example, a 1064nm beam can be converted to a 532nm green beam or a 355nm ultraviolet beam by using a nonlinear crystal.
• Better thermal management: A DPSS laser using NdYAG can have better thermal management than a direct diode laser, as the heat generated by the pump diode is separated from the gain medium. This can reduce the thermal effects on the beam quality and stability.

However, using 808nm + NdYAG for producing 1064nm laser also has some disadvantages, such as:

• Higher cost: A DPSS laser using NdYAG is more expensive than a direct diode laser, as it requires more components and alignment. The pump diode and the NdYAG crystal also have lower efficiency than a direct diode laser.
• Higher complexity: A DPSS laser using NdYAG is more complex than a direct diode laser, as it requires more optical elements and electronics. The DPSS laser also needs cooling and maintenance to ensure its performance.
• Lower reliability: A DPSS laser using NdYAG is less reliable than a direct diode laser, as it is more sensitive to environmental factors such as temperature, humidity and vibration. The DPSS laser also has a shorter lifetime than a direct diode laser.

Some advantages of 1064nm wavelength are:

• It can penetrate deeper into biological tissues than visible or ultraviolet light, which makes it suitable for medical applications such as laser hair removal, treating vascular skin lesions and laser-induced thermotherapy.
• It can interact strongly with many materials, such as metals, ceramics and plastics, which makes it useful for material processing and analysis such as laser cutting, welding, drilling and laser-induced breakdown spectroscopy.
• It can be easily converted to other wavelengths by nonlinear optical processes, such as frequency-doubling, tripling or mixing. For example, a 1064nm beam can be converted to a 532nm green beam or a 355nm ultraviolet beam by using a nonlinear crystal. This allows for applications such as ultraviolet lithography and LASIK eye surgery.
• It can be efficiently coupled into optical fibers, which enables flexible delivery and remote operation of the laser.

Some disadvantages of 1064nm wavelength are:

• It has much lower scattering intensity compared to shorter wavelengths, which means that it requires higher laser power and longer exposure times to achieve the same signal level. This increases the risk of sample damage and limits the sensitivity of some techniques such as Raman spectroscopy.
• It has lower brightness and resolution than shorter wavelengths, which means that it cannot achieve precise and accurate patterning or correction of very small features. This limits its applications in nanotechnology and microfabrication.
• It is invisible to the human eye, which makes it harder to align and focus the beam. It also poses a higher safety hazard than visible light, as it can cause eye damage without being noticed.

• 1064nm laser has a lower absorption by melanin than 808nm laser, which means that it can penetrate deeper into the skin and target the hair follicle more effectively. However, it also means that it requires higher power and longer exposure time to achieve the same result as 808nm laser.
• 1064nm laser has a lower scattering intensity than 808nm laser, which means that it can produce a more collimated and focused beam. However, it also means that it has lower sensitivity and resolution for some techniques such as Raman spectroscopy.
• 1064nm laser has a higher versatility than 808nm laser, as it can be easily converted to other wavelengths by nonlinear optical processes. For example, it can be frequency-doubled to produce a 532nm green beam or frequency-tripled to produce a 355nm ultraviolet beam. This allows for more applications such as ultraviolet lithography and LASIK eye surgery.
• 1064nm laser is more suitable for darker skin types than 808nm laser, as it has a lower risk of causing skin damage or pigmentation. However, it is also more dangerous for the eyes, as it is invisible to the human eye and can cause eye injury without being noticed.

Therefore, it is not possible to replace 1064nm laser with 808nm laser in all applications, as they have different advantages and disadvantages depending on the purpose and the desired performance. Some applications may require a specific wavelength or a combination of wavelengths to achieve the best results. For example, laser hair removal may use a triple-wavelength diode laser that combines 755nm, 808nm and 1064nm lasers to target different hair types and skin tones.