An. Mortensen et al., A HADAMARD-MULTIPLEXED SPECTROMETER BASED ON AN ACOUSTOOPTIC TUNABLE FILTER, IEEE transactions on instrumentation and measurement, 45(2), 1996, pp. 394-398
This paper presents a Hadamard-multiplexed spectrometer based on an ac
ousto-optic tunable filter (AOTF). The multifrequency capability of th
e AOTF enables it to be operated in a multiplexed mode. The AOTF can t
hen be operated at lower power to obtain improved passband characteris
tics without a reduction in the signal-to-noise ratio as compared to a
higher-power, nonmultiplexing instrument. An expandable, PC-based spe
ctrometer has been developed to illustrate this technique, The current
implementation provides seven-frequency Hadamard multiplexing and col
lects the spectra in multiplexed blocks. The AOTF is controlled via IE
EE-485 bussed VHF synthesizer modules based on a hybrid DDS/PLL techni
que, The modular design allows convenient system expansion, The design
of and specifications for this instrument are discussed.