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LGS Switch Crystal

POC-OC-122492-LGS Switch Crystal

  • High electro-optic and piezoelectric performance, making it ideal for advanced laser applications.
  • Broad transmission range from UV to infrared (180 nm–8 µm).
  • Exceptional laser damage threshold (>1 GW/cm² at 1064 nm).
  • Low acoustic velocity and high optical homogeneity for precision laser modulation.
  • Excellent thermal and mechanical stability, suitable for high-power and pulsed laser systems.

Customizable Components Available for This Material to Meet Your Specific Needs!

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The LGS Switch Crystal (Langasite, La₃Ga₅SiO₁₄) is a multifunctional crystal widely used in laser modulation and frequency conversion systems. With high electro-optic coefficients and a broad transmission range spanning ultraviolet to infrared (180 nm–8 µm), LGS crystals are a versatile solution for applications requiring fast laser pulse modulation and precise beam control.

LGS is highly favored for its robust thermal and mechanical stability, making it an excellent candidate for high-power laser systems, even under extreme environmental conditions. Additionally, it possesses a low acoustic velocity, minimizing acoustic losses and enabling high-performance Q-switching and electro-optic modulation. The high laser damage threshold (>1 GW/cm²) further ensures reliability in demanding applications like scientific research, medical laser systems, and industrial laser processing.

 

General Applications and Examples

LGS Switch Crystals are designed for applications in high-energy and precision laser systems, including:

  • Electro-Optic Q-Switches: LGS is an excellent material for Q-switching in lasers used for material processing, micromachining, and laser marking. Its high optical transparency and robust mechanical properties allow it to operate reliably under high power.
  • Laser Modulation: Ideal for precision control of laser pulses in research and medical laser systems, such as in dermatology and ophthalmology.
  • Acousto-Optic Devices: LGS crystals, with their low acoustic velocity, are ideal for acousto-optic modulators used in high-resolution imaging and spectroscopy.
  • Scientific Research: Its high optical homogeneity and damage threshold make LGS a preferred choice for cutting-edge scientific experiments involving high-power laser systems.
  • Industrial Applications: Widely used in manufacturing processes like laser drilling, cutting, and micromachining, where high accuracy and reliability are paramount.

For instance, in industrial laser micromachining, LGS-based Q-switches enhance production speed and precision by enabling rapid pulse modulation, improving efficiency and reducing material waste.

Chemical and Structural Properties

Property

Value

Chemical Formula

La₃Ga₅SiO₁₄

Crystal Structure

Trigonal

Transmission Range

180 nm–8 µm

Melting Point

~1470°C

Density

5.75 g/cm³

Thermal Expansion Coefficient

6.1 × 10⁻⁶/°C

Laser Damage Threshold

>1 GW/cm² @ 1064 nm

Acoustic Velocity

~2800 m/s

Refractive Index

~1.87 (at 1064 nm)

Optical, Laser and Nonlinear Optical Properties

Optical Property

Value

Transparency Range

180 nm–8 µm

Electro-Optic Coefficients

r11 = 2.3 pm/V, r41 = 1.8 pm/V

Refractive Index

1.87 (at 1064 nm)

Dielectric Constant

ε = 18 (static dielectric constant)

Laser Damage Threshold

>1 GW/cm² @ 1064 nm

Acoustic Loss Coefficient

Low

Piezoelectric Coefficient

d11 = 6.8 × 10⁻¹² m/V

Standard Fabrication Specifications

Parameter

Specification

Clear Aperture

90% of central diameter

Surface Flatness

<λ/8 @ 632.8 nm

Surface Quality

10-5 Scratch-Dig

Parallelism

<10 arc seconds

Perpendicularity

<5 arc minutes

Wavefront Distortion

<λ/8 @ 632.8 nm

Thickness Tolerance

±0.1 mm

Spectrum Transmission Curve:

Note: Transmission curve data is available upon request. Please contact POC for detailed spectral transmission performance or customized spectral data.

POC-LGS Crystal Spectrum Transmission Curve

Coating Specification:

Standard coatings are available to enhance the optical performance of LGS Switch Crystals:

  • Anti-Reflective Coating: AR coatings for 1064 nm or other custom wavelengths with reflectance <0.2%.
  • High-Damage Threshold Coatings: Coatings to sustain power densities >1 GW/cm².
    Customized coating options are available upon request for specific applications.
  • Adhesion Test Compliant with MIL-C-675C military standards, an adhesion test involved applying a tape that meets LT-90 specifications onto the lens film layer. The tape was affixed fully and then removed vertically. This procedure was performed three times, resulting in no blistering or peeling.
  • Temperature Test In line with MIL-C-675C specifications, test pieces were subjected to temperatures of -62±1℃ and 71±1℃. After maintaining them at room temperature (16℃~32℃) for two hours, the adhesion test was repeated, confirming no film detachment.
  • Abrasion Resistance Test Conforming to MIL-C-675C and CCC-C-440 standards, the abrasion resistance test involved a gauze tester applying a minimum force of 1.0 lbs (0.45 kg) to the film. This was repeated 25 times with gauze widths of 1/4 inch (6.4mm) and 3/8 inch (9.5mm), ensuring no damage occurred to the film surface.
  • Humidity Test Under MIL-C-675C criteria, the test piece was placed in a controlled temperature and humidity chamber set to 49 ±2℃ and 95%~100% humidity for 24 hours. The film remained intact, with no peeling, scratches, or other defects.
  • Solvent and Cleaning Testing Following MIL-C-675C specifications, test pieces were exposed to room temperature conditions (16℃~32℃) and tested with acetone and alcohol for at least 10 minutes each. After air drying and subsequent cleaning with a cotton cloth soaked in alcohol, the film surface showed no signs of peeling or scratches.
  • Salt Spray Test After 100 hours in a 35°C environment with a 5% saltwater concentration, the film showed no signs of damage.

POC Strength and Capabilities

Photonics On Crystals (POC) specializes in the processing and customization of LGS Switch Crystals to meet various industry demands.

  • Customization Options: POC offers tailored solutions for dimensions, coatings, and application-specific requirements.
  • Quality Assurance: All crystals undergo rigorous quality checks to ensure optical and physical homogeneity.
  • Expertise: POC’s advanced manufacturing capabilities ensure precision and high-performance outcomes, even for challenging laser environments.
  • Global Reach: POC serves industries worldwide, providing reliable and scalable solutions for laser systems.

Standard Products

POC offers a range of standard LGS Switch Crystal products, with customization options available for unique requirements.

Product Code

Dimensions (mm)

Coating Option

Price (USD)

LGS-001

10x10x5

AR @ 1064 nm

$2500

LGS-002

15x15x10

Custom Coating

$3200

LGS-Custom

Custom Dimensions

Application Specific

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Note: Pricing is approximate and may vary based on order quantity and customization requirements

POC-OC-122492-LGS Switch Crystal

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