As an educational Raman system, EduRam is designed for the beginner of Raman spectroscopy to operate manually the essential components of Raman system.
Dimension : 330 X 550 X 200 mm
Components : Laser, Bandpass filter, ND filter, Mirror, Diaphragm, Beam splitter, Objective lens, Sample holder, Longpass filter, Optical fiber, Compact spectrometer, Computer, Bread board, Optical mount, Dark room, etc.
Configuration of Raman open-System
A Raman system is an integrated system which is composed of various optical devices and a spectrograph with a detector. To establish a micro-Raman system on the optical table, the following components are necessary;
Monochromatic light source: Laser
Bandpass filter: Purifies laser beam transmitting the specific frequency of laser.
Mirror, Diaphram, Beam splitter: Needed to align laser beam path.
Microscope: Enables stimulate a sample by laser through the objective lens which also accepts scattered light from the sample.
Longpass filter or Notch filter: Cuts the light from Rayleigh scattering, and transmits light from Raman scattering.
Spectrograph with Detector: Detects light dispersed into different wavelengths.
Computer & Software: Analyze the signal from detector.
The process of measuring Raman signal with the components is as follows;
1. Purified laser wavelength by passing through the bandpass filter should be aligned by two mirrors and diaphrams.
2. A beam splitter suitable for the laser wavelength should be positioned on the beam path at 45 degree, then half of the light reflects from the beam splliter, the other half transmitting. The reflected beam enters the objective lens of the microscope.
3. The laser beam passes through the objective lens, and interacts with the material on the sample stage. Most of the light scatters elastically from the material, the Rayleigh scattering, while very little part of the light scatters inelastically, which is the Raman scattering.
4. The scattered light passes back through the objective lens, goes back to the beam splitter. Again, half of the light transmits, and the other half reflects back to the origin.
5. The transmitted light through the beam splitter arrives at the longpass filter or notch filter. These filters reflects Rayleigh scattered light and let the Raman scattered light pass through. The Raman scattered light is gathered by a lens and goes into the slit of the spectrometer.
6. Inside the spectrometer, the Raman scattered light disperses into individual wavelengths by a grating, then arrives at the detector.
7. The electric signal of the detector is converted to digital signal. Eventually, the analysis software shows Raman spectrum of the material.
Commercial Raman systems covers all the components inside a neat house. So, the beginners could not have such opportunities of observing and handling the essential components of a Raman system. RamanLab designed a compact Raman open-system for the beginners to experience the principle of Raman system by their own eyes and hand. Users can discipline the principle of Raman spectroscopy by themselves with EduRam. As all the optical components are of high quality, addition of a microscope and research-grade spectrometer can makes a good research-grade Raman system.