SnRI’s instruments provide versatile platforms for turnkey and custom research and development Raman systems. From microfluidics to nanomaterials we have off-the-shelf solutions for the most challenging applications.
The SnRI Advantage
Our experienced engineering and production teams design and manufacture unique state-of-the-art Raman systems. These experienced teams develop the best cost performance Raman analyzers in the industry. Some of the features of our spectrometers are below.
Sensitivity and limits of detection depend on the signal-to-noise of the spectrometer. The signal-to-noise relates to the laser source, detector sensitivity, optical throughput, and supporting electronics. We define the signal-to-noise as the ratio of a peak to the noise of the baseline.
SnRI spectrometers are built with the highest quality cooled CCD detectors with noise reducing electronics and software. Our optical throughput is optimized with all on-axis optical components which eliminates astigmatisms and maximizes the Raman signal on the low noise linear CCD arrays. This combination of integrated laser and spectrometer produces the best high signal to noise Raman spectrometers.
One of the characteristics of dispersive spectroscopy is the relationship between light collection and resolution. This relationship is inverse: the more light you collect the lower the resolution. This is also characterized as the etendue of the system. With conventional spectroscopic instruments a large interrogation area (large laser spot) would require a large aperture in the spectrometer to efficiently collect all of the laser light. Increasing the aperture has a negative effect on the valuable information about the material spread over the detector resulting in poor spectral resolution.
For pure samples a tightly focused laser beam and small spectrograph aperture may be sufficient. However, when the sample is heterogeneous or sensitive to the high laser power, found in a tightly focused beam, it is necessary to expand the beam size or reduce the laser power. One example of a patterned rastering technology that overcomes the problem of etendue loss with large interrogation areas is ORS (Orbital Raster Scan) technology.
Raster scanning provides three main advantages:
- Higher laser powers can be employed because the laser spot does not rest on the same location. Even nanoparticles in suspensions can be susceptible to sample burning over periods of time.
- Secondly the rastered beam collects data at several locations of the sample providing a more reproducible result, which eliminates “hot-spot” effects.
- It enables a very high throughput, signal-to-noise, high resolution measurement system without loss on “etendue” that can occur in a conventional Raman spectrometer.
Raman spectrometers provide simple easy to use methods to study chemistry, physics, geology or the engineering sciences. Our systems are not only a low-cost solution to teaching, they offer the economy of space with their compact design. We have a collection of prepared teaching labs emphasizing all of the chemical divisions and materials sciences.