Lars Lading, Carsten Dam-Hansen, and Erling Rasmussen, "Surface light scattering: integrated technology and signal processing," Appl. Opt. 36, 7593-7600 (1997)
The miniaturization of surface-scattering instruments for measuring
viscoelastic properties is investigated. The concepts are based on the use of
holographic optical elements and integrated optics. Compact forms of optics
that provide the necessary spatial and angular selections are devised. Four
systems representing increasing levels of integration are considered. It is
demonstrated that efficient signal and data processing can be achieved by
evaluation of the statistics of the derivative of the instantaneous phase of
the detector signal.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
The absolute numbers depend on the specific type
of detectors and the wavelength at which the detectors are used. At a wavelength of 850
nm, a very high quantum efficiency implies >70%, a high quantum efficiency implies
>50%, and a low quantum efficiency implies <10%.
Table 4
Key Parameters of an HOE Configuration
Laser
3 mW, 670 nm
Detector
Si diode
HOE grating
gx, 600 lines/mm; gy,
10 and 12 lines/mm
HOE imaging lens
Lens with f = 4 mm and a carrier g = 600 lines/mm
HOE FT lens
f = 10 mm, carrier g = 600
lines/mm
Spacing between substrates
5 mm
Spacing between lower substrate and surface
10 mm
Table 5
Specifications for the Diffraction Gratings Multiplexed in a Photorefractive Crystal, including Diffraction Efficiency (η), Refractive-Index Modulation (Δn), and Angular Width (ΔΘ)
Parameter
Transmitter and Receiver Gratings for Signal Beams
Transmitter Gratings for and Reference Beam
η (%)
50
0.5
Δn
7 × 10-5
6 × 10-6
ΔΘ (mrad)
0.2
0.2
Tables (5)
Table 1
Component and Surface Specification Assumed to be
Given
Component
Value Unit
Laser power
3 mW
Laser wavelength
0.85 µm
Laser noise (rms/laser power)
0.01%
Laser noise bandwidth
100kHz
Overall quantum efficiency
0.6
Detector gain
1
Detector noise (dark current + thermal)
10-14 A/Hz1/2
Relative instrumental broadening
10%
Refractive index of liquid
1.38
Diffraction efficiency of surface in the selected spectral region
10-7
Relative spectral broadening caused by capillary-wave decay
10%
Center frequency of detector signal
5 kHz
Reference beam power for maximum signal-to-noise ratio
The absolute numbers depend on the specific type
of detectors and the wavelength at which the detectors are used. At a wavelength of 850
nm, a very high quantum efficiency implies >70%, a high quantum efficiency implies
>50%, and a low quantum efficiency implies <10%.
Table 4
Key Parameters of an HOE Configuration
Laser
3 mW, 670 nm
Detector
Si diode
HOE grating
gx, 600 lines/mm; gy,
10 and 12 lines/mm
HOE imaging lens
Lens with f = 4 mm and a carrier g = 600 lines/mm
HOE FT lens
f = 10 mm, carrier g = 600
lines/mm
Spacing between substrates
5 mm
Spacing between lower substrate and surface
10 mm
Table 5
Specifications for the Diffraction Gratings Multiplexed in a Photorefractive Crystal, including Diffraction Efficiency (η), Refractive-Index Modulation (Δn), and Angular Width (ΔΘ)
Parameter
Transmitter and Receiver Gratings for Signal Beams
Add to BibSonomy