Galvo Mirror Materials and Applications: A Comprehensive Guide

Galvo mirrors are the core components of laser galvanometer systems. Their performance directly impacts the accuracy, speed, and stability of laser scanning. Choosing the right mirror material is critical for system design, as different applications demand varying optical, mechanical, and thermal properties.

This article provides an in-depth overview of the four most commonly used galvo mirror materials: Silicon, Quartz, Silicon Carbide (SiC), and Beryllium, covering their physical properties, manufacturing processes, costs, and typical applications.

1.Silicon Galvo Mirrors

Density: ~2.33 g/cm³, lightweight.

Properties: High hardness, good thermal conductivity, stable optical surface, suitable for high-speed scanning. Can handle lasers below 2000W at 1064nm when coated.

Manufacturing: CNC precision machining + gold coating.

Cost: $5–10/cm², very cost-effective.

Applications: Laser marking, precision machining, laser cleaning, 3D printing.

Silicon galvo mirror is lightweight and economical, with good hardness and thermal conductivity. Edge-trimming and thinning are often applied for 20mm–30mm mirrors to reduce inertia, ensuring high-speed galvo scanner operation. Silicon mirrors are widely used in general laser marking, precision processing, laser cleaning, and 3D printing applications.

2.Quartz Galvo Mirrors

Density: ~2.20 g/cm³, slightly heavier than silicon.

Optical & Thermal Properties: Very low thermal expansion coefficient (0.55×10⁻⁶/℃), stable over 20–300℃. Transmission >90% from 190–3500nm.

Manufacturing: Diamond cutting + ion beam polishing.

Cost: $20–50/cm². 

Applications: OCT imaging, confocal microscopy, semiconductor inspection, high-power laser welding.

Quartz galvo mirrors are slightly heavier but offer excellent thermal stability and a wide transmission spectrum, from UV to near-infrared. In high-power applications, air cooling is often used to prevent deformation. Quartz mirrors are ideal for medical imaging, semiconductor inspection, and high-precision welding.

3.Silicon Carbide (SiC) Galvo Mirrors

Hardness & Strength: Mohs ~9.5, >300MPa, highly wear-resistant and impact-resistant.

Weight Optimization: Honeycomb back structure to reduce weight, suitable for high-speed scanning.

Thermal Stability: Similar to silicon, low thermal expansion.

Manufacturing: Reaction Bonding (RB) + Chemical Vapor Deposition (CVD) + precision grinding + ion beam polishing.

Surface Accuracy: λ/100, Ra<0.5nm.

Applications: High-speed galvo scanners, solar cell scribing, medical laser scanning systems.

Silicon carbide galvo mirrors combine ultra-high hardness, lightweight, and excellent dimensional stability, making them ideal for high-speed scanning and industrial applications. Honeycomb back design reduces inertia and improves scanning efficiency.

4.Beryllium Galvo Mirrors

Density: 1.848 g/cm³, the lightest metal with high stiffness.

Mechanical Properties: High bending strength, maintains shape stability during high-speed vibrations.

Coating: Nickel + dielectric coating to enhance reflectivity; coating may degrade over time.

Safety: Toxic; requires strict protective handling.

Manufacturing: Vacuum melting + nickel coating.

Applications: Resonant scanners (up to 12kHz), ultra-fast galvo scanning systems.

Beryllium galvo mirrors are extremely lightweight and rigid, suitable for high-frequency resonant scanners. They allow scanning speeds about 30% faster than SiC mirrors but are costly and require careful safety measures due to toxicity.

Comparison of Galvo Mirror Types

Conclusion & Application Recommendations

Choosing the right galvo mirror material requires balancing laser power, scanning speed, optical performance, thermal stability, and cost:

Silicon Galvo Mirrors – Economical, lightweight, and suitable for mid-power applications like laser marking and 3D printing.

Quartz Galvo Mirrors – High optical clarity and thermal stability, ideal for medical imaging and semiconductor inspection.

Silicon Galvo Carbide Mirrors – High-speed and large-area industrial applications, offering precision and durability.

Beryllium Galvo Mirrors – Ultra-light and stiff for high-frequency resonant scanners; cost and safety considerations restrict widespread use.

When designing a galvo scanner optical solution, choosing the right galvo mirror material is essential. At Scanner Optics, our galvanometer laser scanner is engineered with optimized mirror materials to achieve high precision, stability, and cost-effectiveness for diverse laser applications.