What is the FWHM of the channels, what is the smile of the camera

The FWHM (Full Width at Half Maximum) of the ULTRIS X20 is designed to be 10 nm for every channel in the 350-1000 nm range. As shown in the image below (FWHM), the design is met in praxis, even in the whole image area of the camera. The peak positions can be found more precisely than the sampling interval of the camera shows. Using a weighted peak position, we find the maximum of the 532 nm Laser radiation @ 531.09 nm.

The spectral filters of the ULTRIS X20 are produced linearly. Each channel is separated by 10 nm and offers 10 nm FWHM (see Figure Filter Positions). Therefore, the results in other channels are similar to the given example @ 532 nm.

Fig 1: FWHM of the ULTRIS X20 for the measurement of the spectral signature of a 532 nm frequency doubled ND-Yag laser. The measurement was performed on 100 random positions in the image of the ULTRIS X20 and all 100 curves are plotted here separately. 

In Summary

The ULTRIS X20 has an unprecedented wavelength accuracy over all channels and places in the image. For the user, the system has a negligible amount of smile (below 1nm). This is made possible by the physically easy-to-understand working principle of the device and our extensive calibration (patent pending). In this calibration, each single pixel in the 20MP array is calibrated for its precise central wavelength position with a monochromatic measurement of 300-1000 nm.