Cold light filters picture, Cold mirror


Technical, heat transmitting cold mirrors

Special Properties

  • Very high optical reflectivity
  • Broadband infrared transmittance (up to 2.500 nm)
  • Excellent reflection uniformity
  • High operating temperature
  • Constructed to reflect the visible spectrum
    and to transmit and filter the infrared
  • Temperature resistant borosilicate glass substrate
  • Good mechanical stability

Typical Applications

  • Highly efficient front-surface-mirrors
  • Heat transmitting optical filters in lighting systems
  • Mirror for cold light sources
  • Dielectric mirrors for sensor technology
  • Cost effective dielectric 45° laser optics
  • Dichroic lighting optics
  • Scanners and bar code reader optics
  • IR-filters
  • Laser beam separation

What are cold mirrors and what are they used for?

Cold mirrors are dichroic optics, that operate in the opposite manner as heat reflecting filters do. Hot mirrors are designed for maximum optical transmittance in the visible spectrum and maximum reflectivity in the near infrared, whereas cold mirrors are optimized for maximum reflectivity of VIS-wavelengths and best possible transmittance of the infrared range (thermal energy). So, cold mirrors work as heat transmitting filters and at the same time they offer a very high visible light reflectivity. Our SHD-mirrors are flat, dielectric, front surface coated optics, that allow an almost loss-free deflection of visible light at an angle of incidence of 45°. They are used for applications, that require a good imaging quality and a very strong reflectivity in the wavelength range of approximately 400-700 nm. The dichroic mirror coatings very effectively filter out infrared-energy from a illumination source, beginning at approximately 800 nm up to about 2500 nm, which results in a cold light beam reflected by 45°. This very broadband transmissivity of the coatings and the glass substrate in the infrared wavelength range is a great advantage over hot-mirrors in terms of the efficiency of removing thermal energy from a light beam. This is because the IR-blocking range of a hot mirror is usually limited to a much more narrow bandwidth for physical reasons.


The special features of our SHD cold mirror

The SHD optical mirror coatings are coated on temperature resistant glass substrates. Hence, the SHD mirror is a very good choice for very efficient heat- / light separation systems, because most of the IR-energy is removed by IR-transmissivity and therefore cannot heat up the filters as much as it is the case with absorbing filters. The non-metallic multilayer thin film layer coating design features an outstanding temperature resistance, and shows a distinguished resistance against moisture and abrasion. If required, the optical coating system of our SHD cold mirrors can be modified for different transmission-, reflectivity- and filter ranges, as well as in regards to the cut-on and cut-off points and the incidence angle. Other glass substrates are optionally possible too. Please use our customized optics inquiry sheet, to conveniently inquire for your individually tailored optical mirror coating design for your special application. For further information, please use our information questionnaire.


How to buy the mirrors

We are not limited to a small stock delivery program of optics with predefined dimensions. Our strength is to be just as quick or even quicker with individually sized optics than you might be used to, when you buy catalog items. In other words, you can order the cold mirrors exactly at the size you need them, with the advantage of a short lead time.

To request a quotation for cold mirrors of the SHD series with individual dimensions, please click the button below:


Request for Quotation

48h- Express Service terms & conditions

48-h Express Optics Service available




SHD, reflectivity

View reflectivity spectrum of the SHD mirror



Glass Substrate


  • R > 99 % for single wavelengths
  • Ravg > 97 % at 400 - 690 nm at i = 45°
  • Tavg > 85% at 800 - 2500 nm
  • Other wavelength ranges or customer specific
    cut-off and cut-on points or different angle of incidence on request


  • Depending on glass substrate material
    and glass thickness

Surface Quality

  • typ. 80-50 scratch & dig (MIL-0-13830A)
  • Other on request

Standard Thicknesses

Adherence and Abrasion Resistance

  • Adherence according to MIL-C-675 C (tape test)
  • Abrasion resistant according to MIL-M-13508 C


All given details and specifications are mean reference values and are not guaranteed. In addition, please consider the "Notes on specifications"