Using the Near-Field Near-Infrared (NIR) Spectroscopy System, the spot size of near-field light generated from the near-field probe is dependent only upon the aperture size, not the wavelength.


Rapid expansion of the Internet Telecommunications (IT) industry in recent years has promoted extensive research and development on optical elements for communication in the 1.3-1.5 micron wavelength range.

Due to the nanoscale design of devices such as the highly efficient laser diodes that generate light at these wavelengths, the photo diodes that function as detectors, and the waveguides that form optical circuits, conventional spectral analysis methods are not able to analyze these items.

By using near-field light as the excitation source, samples can be examined in the near-infrared range with spatial resolutions at or below the source wavelengths utilizing a high sensitivity FT-NIR spectrometer.

System Features

  • Covers the near-infrared range used for the optical communications field
  • Combines near-field illumination with a high-sensitivity FT-NIR to provide luminescence spectroscopy in the near-infrared range
  • Topographic mapping of almost any sample; organic, inorganic, metal or biopolymer, etc.
  • For low temperature experiments, the NFS-320FT includes a He gas-flow cryostat for cooling to 10K or less


Combining a high sensitivity FT-NIR spectrometer with an InGaAs detector allows detection of wavelengths exceeding 1µm, beyond the range of a Si detector. The figures below outline the data collected by the NFS-220FT for the surface of an Er3+ (Erbium) doped fiber, the optical fiber used for optical signal amplifiers in the 1.55 micron band.

‘A’ illustrates the luminescence spectrum for the sample with a readily observable peak corresponding to the luminescence of Er3+ near the core. ‘B’ is a diagram of the luminescence intensity distribution, and ‘C’ displays the cross-section of the intensity distribution.

The figures demonstrate that, even for the near-infrared range, spectral analysis can be done at spatial resolutions at or below the source wavelengths using near-field analysis methods.

Luminescence Spectrum
A) Luminescence Spectrum
Luminescence Intensity Distribution
B) Luminescence Intensity Distribution
Cross Section
C) Cross Section


Measurement ModesIllumination-collection, collection, external light introduction mode, and standard light source introduction mode for wavelength modification
LasersMaximum of 2 laser sources can be installed
Light Path SwitchingComputer controlled
Standard SourceGreen laser at 532 nm
External Laser Introduction1 port
Fourier Transform SpectrometerWavelength range: 850 - 1500 nm
Wavelength resolution: 1 nm (around 1 micron)
Detector: InGaAs
Interferometer: 90º Michelson interferometer
Beam splitter: Si on CaF2
Cryostat (NFS-320FT)He gas flow type – He gas introduced by transfer line
Stage Range20 x 20 µm; Height: 8 µm
Control PCWindows 2000/XP OS
Image AcquisitionVideo capture card
SoftwareFeedback signal monitor and near-field mapping measurement software, 3-D display software, CCD image display software for probe observation, mapping analysis software, spectral analysis software
System Size1600 x 750 x 1500 mm (W x D x H)
Weight80 kg (main unit), 76 kg, 300 kg (vibration isolation table)
Power RequirementAC100 V ±10%, 250 VA (main unit), 130 VA (FTIR), 100VA (PC)
Other RequirementsNitrogen or air source for vibration-isolation table, 0.3 to 0.8 MPa (50-100 psi)