CAS 140CT-HR - High resolution array spectroradiometer

The high resolution CAS 140CT-HR is based on Instrument Systems’ high-end array spectrometer CAS 140CT, a product line that has achieved extraordinary success around the world. The CAS 140CT-HR is particularly designed for the measurement of narrow band emitters, e.g. laser diodes. Therefore, the spectroradiometers combine the demands of high spectral resolution and short testing times for sophisticated measurement tasks in production and laboratory environments.


All CAS 140CT-HR models are offered with a PTB traceable calibration. They are factory-equipped with a USB interface and optionally available with PCIe interface for extended triggering possibility. The integrated density filter wheel and the dark shutter additionally facilitate fully automated measurements over an extremely broad detector signal range. The spectroradiometers can be operated with Instrument Systems’ SpecWin Pro software for advanced laboratory applications. In addition, they are compatible with DLL and LabVIEW drivers for creating proprietary programs and integration into production equipment.


  • Spectral resolution down to 0.2 nm FWHM (0.08 nm data point interval)
  • Typical measuring ranges of 80, 120 and 160 nm customized within the spectral range from 800 to 1000 nm (further spectral ranges available on request)
  • High-end actively cooled CCD detector for utmost measuring sensitivity and stability
  • Integrated density filter wheel enables an extremely wide intensity measuring range
  • USB interface and PCIe interface (optional)
  • Software solutions for laboratory and production applications


  • System solutions particularly designed for testing narrow band emitters, e.g. laser
    diodes and VCSELS
  • Very precise characterization of narrow band emitters with very short pulses in laboratory and production applications
  • Short testing times enable industrial quality control in the production line

Technical Specifications:

CAS 140CT-HR Array Spectroradiometer
Accessible spectral range800 - 1000 nm 1
DetectorBack-thinned back-illuminated CCD actively cooled to -10°C
Number of pixels1024 x 128
Gratings1200, 1500, 1800 lines/mm
Measuring ranges (typical)80 – 160 nm
Spectral resolution (typical)0.2 – 0.4 nm
Data point interval (typical)0.08 – 0.16 nm
Wavelength accuracy 2)± 0.05 nm
Integration time 9 ms – 65 s (PCIe); 10 ms – 65 s (USB)
Sensor dynamic range 3)30000 : 1

1 Further spectral ranges upon request.
2 Applies to Penray lamp or laser.
3 From CAS trigger until measurement finish.

Optical design of the

The Crossed-Czerny-Turner spectrograph is housed in a mechanically robust block. The incident light is first collimated by a concave mirror and guided on to the diffraction grating, where it is spatially split into its different spectral components. A second concave mirror focuses the various spectral components of the light onto different columns of the CCD detector, thus capturing the light's spectrum in a single acquisition.