Page 5 - Shimadzu SolidSpec-3700i

High Sensitivity

High accuracy for transmittance and reflectance is required for the measurement of optical parts. Comparison of Two-Detector and Three-Detector Models
The SolidSpec-3700i/3700i DUV have three detectors which cover the range from ultraviolet to near-infrared.
The sensitivity in the near-infrared region is significantly enhanced by using both InGaAs and cooled PbS An InGaAs detector is used, in addition to the photomultiplier tube (PMT) and cooled PbS detectors.
detectors. Highly accurate and highly sensitive spectra are obtainable from ultraviolet to near-infrared. That results in less noise than the two-detector (PMT and PbS) model, especially in the region detected by the InGaAs
detector (900 to 1600 nm).

Three Detectors 1.000 70.000

60.000

40.000
0.500
T% T%
PbS detector

20.000

InGaAs detector
0.000
0.00
−0.100 −5.000
1000.00 1200.00 1400.00 1600.00 1000.00 1200.00 1400.00 1600.00 1800.00 2000.00
Three detectors attached to the integrating sphere nm nm
: SolidSpec-3700i/SolidSpec-3700i DUV (InGaAS detector) The spectrum above was measured with InGaAs and PbS
PMT detector : 2-detector model (PbS detector) detectors, using a sharp cut filter for near-infrared light. Increasing
the sensitivity in the near-infrared region is especially beneficial for
low-reflectance measurements, such as measuring anti-reflective
Sensitivity Characteristic (AR) coatings used in the optical communications field.
100 Conventional spectrophotometers have used a PMT (photomultiplier
Relative Value (%) PMT tube) for the ultraviolet and visible region and a PbS detector for the High Accuracy Measurement with Minimized Detector Switchover

Noise and Bump
InGaAs
near-infrared region. However, neither detector has much sensitivity
PbS
near the wavelength of 900 nm, preventing high-sensitivity
measurement in this range. Noise and bump caused by detector switchover are minimized to assure accurate measurement.
The SolidSpec-3700i/3700i DUV make it possible to take
0
1000 2000 3000 high-sensitivity measurements in the switchover range by using an 30.000 100.000
Wavelength (nm)
InGaAs detector as shown in the figure on the left.
20.000
90.000
Relationship between Detectors and Measurable Range
T% T%
165 nm 380 nm 780 nm 3300 nm
10.000
UV Visible NIR 80.000
PMT 165 to 1000 nm
InGaAs 700 to 1800 nm 0.000
PbS 1600 to 3300 nm -3.000 70.000
700.00 800.00 900.00 1000.00 1550.00 1600.00 1650.00 1700.00 1750.00
nm nm
The photomultiplier tube detector can be switched to the InGaAs detector in the range from 700 nm to 1000 nm (the
default switching wavelength is 870 nm). The InGaAs detector can be switched to a PbS detector in the range from 1600 nm The transmission spectra of a color filter and polyester film are shown in the left and right figures, respectively.
to 1800 nm (the default switching wavelength is 1650 nm). Noise or bump caused by the detector switchover range at 870 nm and 1650 nm are not observed.

SolidSpec-3700i/3700i DUV
4 UV-VIS-NIR Spectrophotometer 5