Dichroic Mirrors
Spectral Performance and Optical Behavior
Dichroic mirrors can be engineered for a wide variety of spectral functions, including:
Long-wave reflection with short-wave transmission
Short-wave reflection with long-wave transmission
Band reflection with broadband transmission
Compared with metallic mirrors, dichroic designs offer higher reflectivity in the target band, higher transmission outside the stop band, and lower thermal absorption, making them suitable for high-intensity illumination and laser applications.
Because reflection and transmission are achieved through interference, dichroic mirrors maintain excellent environmental stability and long-term spectral consistency when properly designed and coated.
Substrate and Coating Options
Star Optics uses base materials that meet optical standards to manufacture dichroic mirrors. The selected base materials are determined based on the wavelength range and environmental requirements. Our base materials include:
- BK7 optical glass – suitable for visible light and near-infrared applications, with good uniformity and cost-effectiveness
- Fused quartz – due to its low thermal expansion coefficient and high laser damage threshold, suitable for ultraviolet and high-power applications.
- Borosilicate glass – for applications requiring enhanced thermal stability
The functional performance of the dichroic mirror is mainly determined by the stack of dielectric coatings. All coatings are deposited through high-precision vacuum deposition processes to ensure the accuracy of layer thickness, spectral consistency, and good adhesion. Optional protective coatings can also be provided to enhance durability, moisture resistance, and compression resistance.
Factory Standards
At Star Optics, the manufacturing and inspection of all birefringence mirrors are carried out using advanced optical metrology systems to ensure compliance with specified mechanical, optical, and spectral specifications.
Our standards for dichroic mirrors include:
Surface flatness: λ/4
Surface quality: 40-20 scratch dig
Diameter tolerance: +0, -0.1 mm
Clear aperture: ≥90% of diameter
Spectral performance parameters such as reflection band, transmission band, cut-on or cut-off wavelength, and average reflectance or transmittance are verified during production according to customer-defined requirements.
Custom Dichroic Mirror Solutions
In addition to standard designs,Star-Optics offers custom dichroic mirrors tailored to specific wavelength bands, angles of incidence, substrate geometries, and environmental conditions. Our engineering team works closely with customers to optimize coating design and mechanical specifications to ensure reliable performance within the intended optical system.
