Guidelines for the types of reflectors and the use of flat reflectors

Dielectric Film Reflector

1. : Multiple layers of dielectric film are coated on the surface of optical components, causing interference superposition in a certain band, thereby enhancing reflectivity. The dielectric film has a high reflectivity and can be used in a wide wavelength spectral range. The film does not absorb light, making it harder and less susceptible to damage. It is suitable for optical systems with multi wavelength lasers. This type of reflector has a thick film layer, angle sensitivity, and high cost.

Flat Reflector

2. Laser line reflector: The substrate material of the laser line reflector is ultraviolet fused silica, and the high reflection film on its surface is Nd: YAG dielectric film, which is plated by electron beam evaporation and ion assisted deposition. Compared with K9 material, UV fused silica has better uniformity and lower thermal expansion coefficient, which makes it particularly suitable for applications in UV to near-infrared bands, high-power lasers and imaging fields. The common working wavelengths of laser line reflectors are 266 nm, 355 nm, 532 nm, and 1064 nm, with incidence angles of 0-45 ° or 45 °, and reflectivity of over 97%.

Dielectric Film Reflector

3. Ultrafast reflector: The substrate material of the ultrafast reflector is fused silica, and the high reflection film on its surface is a low group delay dispersion dielectric film, which is plated by ion beam sputtering (IBS) process. Fused silica has lower thermal expansion coefficient and extremely high thermal shock stability, which makes it particularly suitable for high-power femtosecond pulse laser and imaging fields. There are four common working wavelength ranges for ultrafast mirrors: 460-590 nm, 700 nm-930 nm, 970 nm-1150 nm, and 1400 nm-1700 nm. The beam is incident from 45 °, with a reflectivity of over 99.5%.

Dielectric film reflector 4. Super reflector: The super reflector is made by plating a multilayer dielectric reflection film with alternating high and low refractive index on the ultraviolet fused silica substrate. By increasing the number of film layers to improve the reflectivity, the reflectivity of the super reflector at the design wavelength can be better than 99.99%, which is suitable for optical systems with high reflectivity requirements.

Dielectric film reflector

5. Metal film reflector: Metal film reflector is very suitable for wide spectrum light source path deflection, and has high reflectivity within a wide spectrum range. Metal films are prone to oxidation, discoloration, or detachment in high humidity environments. Therefore, metal film reflectors are generally coated with a layer of silicon dioxide protective film on their surface to isolate the metal film from direct contact with air and prevent the metal film from being oxidized and affecting its optical performance.

Dielectric film reflector