PHOTON RT LWIR Spectrophotometers


LWIR Transmission and Refection Measurement of Plano Optics at Normal and Variable Angles of Incidence


Accurate and reliable infrared spectral measurements of optical coatings are one of the most critical challenges today. Optical manufacturers around the world specify increasingly sophisticated IR coatings for their planar optics focusing on better detection and identificaion of objects at long distances. Often, the production capabilities for obtaining optical coatings are well ahead of the existing metrological capabilities for certifying their quality.

The PHOTON RT 7512 spectrophotometer is a unique instrument specially designed to effectively meet these challenges. The instrument allows measuring the transmission and reflection of coatings designed for LWIR. An unsurpassed feature of the PHOTON RT 7512 is the ability to carry out automatic measurements at variable angles of incidence up to 60 degrees in polarized light. These non-trivial tests are supported with the built-in feature which accurately compensates for beam displacement at high angles and ensures S-pol and P-pol results in just a few minutes. Maximum thickness of the sample can be a record 40 mm.



  • High accuracy measurements at norrmal and variable AOI
  • Built-in high-contrst poalrizers
  • Extremely low noise measuremets
  • Fully automatic operation



MODEL 7512
Photometric functions %T, %R
Effective wavelength range, µm 7,5 - 12,5
Built-in polarizers, µm 7,5 - 12,5
Optical scheme of monochromator Czerny-Turner
Optics Mirror: Au, Lenses: ZnSe + AR
Measurement of Transmission Variable angle measurements: 0 - 60 deg angles of incidence
Measurement of Reflection

Interchangeable sample stages with fixed angles of incidence: 10, 30, 45 and 60 deg

Reference sample: gold mirror

Turning pitch angle of sample stage 0,01 deg
Beam displacement compensation, mm 40
Unattended polarization measurements with buil-in polarizers S, P, (S + P) / 2
Wavelength sampling pitch, nm 0,5 - 100
Spot size on measured sample, mm 6,0 x 3,0
Ultimate spectral resolution, nm 8 (non-polarized light)
Wavelength accuracy, nm 3,6
Wavelength repeat accuracy, nm + / - 0,9
Photometric accuracy + / - 0,2% (47% T, λ0 = 10,6 µm, AOI = 30)
Photometric repeat accuracy + / - 0,1%
Stability of baseline, % / hour* + / - 0,3%
Light sources

IR lamp

HgAr wavelenth calibration verification lamp


Maximum sample size, mm

150 x 200

Maximum sample thickness, mm 40
Planar sample stage For measurement of transmission and reflection of planar samples with size bigger than 12 x 10 mm
Synchronized positioning Synchronized computer controlled positioning for sample stage and photodetectors unit depending on the chosen photometric function



USB 2.0

Power consumption, Watt


Power input

110-220 VAC, 50-60 Hz

Width x Depth x Height, mm

760 x 340 x 370 (30" x 13,39" x 14,57")

Net weight, kg (lbs)

51 (112)

* 60 minutes warm-up time