Université de Neuchâtel

Dispersive compact Fourier transform spectrometer for the visible

Manzardo, Omar ; Kipfer, Peter ; Herzig, Hans-Peter

In: Technical Digest Series, Fourier Transform Spectroscopy : New Methods and Applications, 1999, p. 165-167

A dispersive compact Fourier transform spectrometer is realized which operates in the visible wavelength range. No moving parts, no imaging system and compactness are the characteristics of this spectrometer. It is based on a novel beam splitter design, which reduces the influence of the size of the light source and therefore the spatial coherence requirements. The effect of dispersion due to an...

Université de Neuchâtel

Improved red color with cholesteric liquid crystals in Bragg reflection mode

Kipfer, Peter ; Klappert, Rolf ; Herzig, Hans-Peter ; Grupp, Joachim ; Dändliker, René

In: Optical Engineering, 2002, vol. 41, no. 3, p. 638-646

The helical pitch of the cholesteric liquid crystal (CLC) can be adjusted to reflect the colors red, green, and blue. Additive mixing of these colors in displays results in multicolor images and it is easy to use pure primary blue and green colors, but the red color is in general very unsaturated. We show by simulations that this poor red color performance is due to reflection sidebands on the...