Ibsen Photonics A/s

Michael Rasmussen

Bjarke Rose

Per Eld Ibsen

Jens Bastue

Claus Friis Pedersen

Chaker Khalfaoui

Ole Jespersen

Nicolai Herholdt-Rasmussen

Thomas Rasmussen

Transmission spectrometers require low levels of background light so that the signal to noise ratio is increased, and also require stable performance over wide temperature ranges. Light reflected by the transmission grating can result in increased background levels. One approach to reducing the background level is to orient the transmissive diffraction grating so that light reflected by the grating is reflected out of the diffraction plane. The temperature-induced wavelength drift of a transmission spectrometer can be due to the frame upon which the transmission grating is mounted. The wavelength drift is reduced by allowing the thermal expansion of the grating to be independent of the frame.

Transmission spectrometer with improved spectral and temperature characteristics

A wavelength division multiplexed device is based on a transmission grating spectrometer having at least two diffractive optical elements. The WDM device provides flexible use and may be widely applied in WDM systems. The device is useful for multiplexing and demultiplexing, channel monitoring, and for adding and dropping channels. The device provides programmability in use as an add/drop multiplexer.

Wavelength division multiplexed device

A method and apparatus for measuring spectral information of light from at least one object includes at least one light detector and at least one transparent body. The transparent body has a front side that has an entrance aperture and at least one reflecting surface. The transparent body also has a back side that includes at least one reflecting surface and an exit surface. The detector is positioned near the exit surface. At least one of the front reflecting surface and the back reflecting surface includes a diffractive optical element arranged to receive diverging light from the aperture. A focusing element focuses diffracted light to the exit surface. The apparatus may comprise multiple channels and may also include a device for measuring a distance to the object.

Spectrometer

Growing community of inventors

Bronshoj, Denmark

Michael Rasmussen