8 New Trend in Instrumentation of NIR Spectroscopy …
201
MEMS element appeared in the first commercial handheld NIR spectrometer,
microPHAZIR (known earlier as PHAZIR). In that case, a programmable Hadamard
mask principle was implemented through the MEMS chip, which contained a large
number of electronically actuated bars resembling a piano keyboard (Fig. 8.6a). A
Hadamard-based spectrometer employs one or two masks, to record more than one
wavelength at a time. Such optical configuration achieves both the Jacquinot and the
multiplex advantages. In the single mask variant, the encoding mask selects half of the
resolution elements and directs the light onto a single element detector. An inverse
Fig. 8.6 Principles of wavelengths selectors built into different handheld NIR spectrometers:
a MEMS Hadamard mask—microPHAZIR, Thermo Fisher Scientific, Waltham, USA; b LVF—
MicroNIR Pro ES 1700, VIAVI, Santa Rosa, USA; c MEMS DMD—implementation of DLP
NIRscan module, Texas Instruments, Dallas, USA; d MEMS Fabry–Perot interferometer—
NIRONE Sensor S, Spectral Engines, Helsinki, Finland e MEMS Michelson interferometer—
NeoSpectra, Si-Ware, Cairo, Egypt; f MEMS Michelson interferometer with a large mirror—
nanoFTIR NIR, SouthNest Technology, Hefei, China. Reproduced from Ref [12]. (CC-BY 4.0
license)
201
MEMS element appeared in the first commercial handheld NIR spectrometer,
microPHAZIR (known earlier as PHAZIR). In that case, a programmable Hadamard
mask principle was implemented through the MEMS chip, which contained a large
number of electronically actuated bars resembling a piano keyboard (Fig. 8.6a). A
Hadamard-based spectrometer employs one or two masks, to record more than one
wavelength at a time. Such optical configuration achieves both the Jacquinot and the
multiplex advantages. In the single mask variant, the encoding mask selects half of the
resolution elements and directs the light onto a single element detector. An inverse
Fig. 8.6 Principles of wavelengths selectors built into different handheld NIR spectrometers:
a MEMS Hadamard mask—microPHAZIR, Thermo Fisher Scientific, Waltham, USA; b LVF—
MicroNIR Pro ES 1700, VIAVI, Santa Rosa, USA; c MEMS DMD—implementation of DLP
NIRscan module, Texas Instruments, Dallas, USA; d MEMS Fabry–Perot interferometer—
NIRONE Sensor S, Spectral Engines, Helsinki, Finland e MEMS Michelson interferometer—
NeoSpectra, Si-Ware, Cairo, Egypt; f MEMS Michelson interferometer with a large mirror—
nanoFTIR NIR, SouthNest Technology, Hefei, China. Reproduced from Ref [12]. (CC-BY 4.0
license)