Ibsen Photonics A/s

Jens Bastue

Bjarke Rose

Michael Rasmussen

Chaker Khalfaoui

Per Eld Ibsen

Claus Friis Pedersen

Nicolai Herholdt-Rasmussen

Ole Jespersen

Keld Theodor

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 are presented for aligning a diffractive WDM device that includes i) a multi-channel, light handling device having a selected channel spacing and ii) a multi-channel signal input unit. The method includes adjusting a direction of incidence of an optical signal from the input unit on at least a first diffracting element of the WDM device so as to set an actual optical channel spacing at an output region of the WDM device to be approximately equal to the selected channel spacing of the multi-channel, light handling device. In the apparatus, the orientation of the light input unit is adjustable in a direction parallel to a diffraction plane of the diffractive WDM device so as to select an actual channel spacing at the multi-channel, light handling device that is approximately equal to the selected channel spacing.

Alignment of multi-channel diffractive WDM device

Growing community of inventors

Frederiksberg, Denmark

Jens Bastue