Crystals commonly used in lasers

Frequency multiplier crystal

Regularity doubling crystal is a type of nonlinear optical crystal made use of for frequency doubling effect.

Basic properties

  • Without main proportion;
  • High transparency of fundamental and dual frequency waves;
  • The quadratic nonlinear electrical polarization coefficient is huge, since the frequency increasing conversion efficiency is proportional to the square of this coefficient;
  • Partial matching ability, especially non-critical matching capability;
  • Stage matching angle and also temperature level tolerance must be in;
  • Excellent optical uniformity, high damage threshold;
  • Secure physical as well as chemical buildings;
  • The development procedure is fairly easy to get crystals huge sufficient to get to usable lengths in the position matching direction.

BBO crystal

BBO nonlinear crystal is a type of nonlinear optical crystal with obvious advantages and good performance. It has an exceptionally broad light transmittance range, exceptionally low absorption coefficient, weak piezoelectric ring impact. Compared to other electro-optic modulated crystals, BBO crystal has a greater termination proportion, a larger stage supporting duty, a higher anti-light damage threshold, broadband temperature matching as well as outstanding optical harmony. It is beneficial to enhance the security of laser result power, specifically for the triple frequency Nd: YAG laser has a variety of applications.

The following are the primary applications for BBO crystal:

  • Used in 1064nm Nd: YAG laser with dual, triple, quadruple and also fivefold frequency;
  • Utilized in color laser and titanium gem laser of dual regularity, triple frequency, sum regularity, distinction regularity, etc;
  • For optical parametric oscillation, amplifier, etc.

Q-switched crystal

Q-switch can be divided right into active Q-tuning as well as passive Q-switch, while active Q-switch can be split into acousto-optical Q-switch and also electro-optical Q-tuning.

Frequently made use of easy Q-switch crystals include: Co: spinel, Cr: YAG, Cr: GSGG, V: YAG, Cr: YSO, etc

Co∶ MgAl2O4 is a very effective saturable absorber for easy Q-switched 1.5 μm “eye security” lasers. The peak power pulsed laser produced by passive Q-switching also has characteristics such as small human eye damage, solid smoke infiltration, low transmission attenuation, and so on. It has a wide range of applications, including room optical interaction, battlefield fast varying, laser radar of unmanned equipment, and so on.

3. Gain medium

Gain medium (i.e., laser working substance) refers to the product system used to realize particle number inversion as well as produce the stimulated radiation boosting effect of light, which can be solid (crystal, glass), gas (atomic gas, ionic gas, molecular gas), semiconductor, fluid, or other media. The primary need of the laser functioning material is to achieve a huge level of fragment number inversion between the specific power levels of the working bits, as well as to maintain this inversion as properly as feasible in the whole laser emission process. To that end, the operating substance must have an appropriate energy degree structure as well as shift characteristics. All lasers can be divided into the following classifications according to the different states of the working product:


(1) Solid laser

Solid (crystal and also glass) laser, the functioning material utilized by this type of laser, is made by blending steel ions which can produce boosted radiation into the crystal or glass matrix to form the luminescence facility;

(2) Gas laser

Gas lasers, they use the functioning material is gas, as well as according to the gas truly generated by the excitation of the functioning particle homes of the different, and better split into atomic gas laser, ion gas laser, molecular gas laser, excimer gas laser, etc;

(3) Liquid laser

Liquid laser, this sort of laser used by the working substances primarily include two kinds, one is organic fluorescent dye remedy, the various other is containing rare earth steel ions of not natural compound service, metal ions (such as Nd) play the function of working particles, and also inorganic compound fluid (such as SeOCl) plays the duty of matrix;

(4) Semiconductor laser

Semiconductor laser, this kind of laser is a particular semiconductor material as the functioning material to generate boosted exhaust, its principle is with a specific excitation way (electrical injection, optical pump or high-energy electron beam injection), between the semiconductor material power band or between the power band as well as the contamination level, with the excitation of non-equilibrium carrier to achieve the bit number turnaround. Hence, boosted emission of light is created;

(5) Free electron laser

Free electron laser, which is an unique kind of new laser, the working material is the directional complimentary electron beam of light moving at high speed in the area routine adjustment of magnetic field, as long as the rate of the cost-free electron light beam can be transformed to produce a tunable systematic electromagnetic radiation, in concept, the meaningful radiation range can transition from the X-ray band to the microwave area, so it has a very attractive possibility.


Er: YAG crystal is a superb 2.94 μm laser crystal, which is commonly utilized in laser medical system as well as various other fields. The Er:YAG crystal is the most important working material of the 3 mm laser and has features such as high slope efficiency, the ability to work at space temperature level laser, a laser wavelength within the risk-free range of human eyes, and so on. The 2.94 mm Er:YAG laser has been widely used in the medical field for surgical procedure, aesthetic dermatology, dental care, and various other therapies.

Advantages of Er:YAG:

  • High slope effectiveness
  • Work at room temperature level
  • The laser working wavelength is fairly risk-free for human eyes

Ti shapphire

Ti-doped sapphire (Ti3+: Al2O3) crystal is the most extensively used tunable laser strong material, with outstanding laser features: a large discharge bandwidth (0.65 – 1.2 μm), excellent thermal, optical, physical, chemical, and mechanical properties. Titanium-doped sapphire lasers and their laser systems are unequaled in their amazing performance as well as the resulting variety of applications, such as proton therapy, accelerator physics, nuclear physics, infrared spectroscopy, and also material characterization.

Erbium glass

Laser glass is a kind of solid laser material based upon glass. It is widely used in various types of solid-state laser light and has become the primary laser material for high power and high energy lasers.

The characteristics of using glass as a laser working object are that it can commonly change the chemical composition as well as manufacturing procedure to obtain numerous essential residential properties, such as fluorescence, high thermal stability, reduced thermal development coefficient, unfavorable temperature level refraction coefficient, high optical uniformity, as well as very easy to obtain a variety of sizes and shapes, small cost, and so on.

Because of its plus size, excellent optical uniformity, low cost, and high production efficiency, laser glass is an essential core product for high-power laser gadgets.

Read more: Passive Q switch crystals

By Nikitha

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