WP 633 Raman Spectrometer

  • f/1.3 input to capture more light
  • Superior optical design based on patented transmissive VPH grating
  • >10x faster data sampling rates
  • TEC cooling option for best SNR
  • Fiber coupled & free space models
  • Compact, robust & configurable
  • Excellent thermal stability
  • *Your best bet for SERS


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Wasatch Photonics offers best-in-class Raman spectrometer systems designed with the WP Raman ƒ/1.3 spectrometer engine to deliver the world’s fastest Raman spectrometers. Wasatch Photonics’ high efficiency HD Volume Phase Holographic Grating and proprietary spectrometer design provides maximum diffraction efficiency and extreme low stray light.

Spectrometer           What you need to know
WP 633L Best general choice for SERS
WP 785L Balances signal with fluorescence background
WP 830L Most popular OEM excitation wavelength
WP 1064L Surprisingly short acquisition times
WP 405L Shorter wavelength, higher signal

This system features a laser, integrated using free-space optics for rapid and low signal measurements. It also has options to add Bluetooth and a battery pack for portable applications. This spectrometer is 2x faster than our fiber coupled spectrometers. Our f/1.3 fiber coupled spectrometers have 10x more throughput compared to an f/4 spectrometer – check out the competitive data below! Custom wavelengths for OEM applications are available upon request.


One of the primary advantages of the Wasatch ƒ/1.3 optical design is high throughput – to our many users, this translates into taking spectroscopic measurements much faster. Deploying a high numerical aperture (NA=0.36), low f-number optical design that utilizes our highly transmissive, patented volume phase holographic (VPH) gratings along with scientific grade, high quantum efficiency back-thinned detectors gives the new WP-series spectrometers the ability to capture signal faster than any f/4 spectrometer.

This impressive speed can be seen in the Cyclohexane Raman Spectra below, which shows the acquisition times for the WP-830-C-50 spectrometer and a competitor’s TEC cooled 830 nm f/4 design spectrometer for a fixed 28 mW of 830 nm excitation laser intensity. The WP spectrometer collects 50,000 counts in 2 s while the competitive f/4 design spectrometer requires 21 s to achieve the same signal intensity. This is even more impressive since the f/4 spectrometer is fitted with a 100 μm slit while the f/1.3 WP spectrometer is fitted with a 50 μm slit.

Measurement time comparison: Wasatch Raman spectrometer vs competitive f/4 spectrometer

If you need to measure flowing materials, reaction changes, or simply don’t want to hold your hand-held device for as long, then our high throughput spectrometers are here to help you.

So why wait? Take high quality Raman spectra over 10 times faster with Wasatch Photonics!


Photons are precious, particularly in Raman spectroscopy, so Wasatch Photonics has designed and built an optical bench that allows you to capture, keep and detect more photons so you can push the boundaries of your science just like they have pushed the boundaries with their designs.

As the figure below shows, for fixed laser excitation wavelength and fixed integration time the WP-830-C detects 10x more signal vs a competitive f/4 spectrometer.

Sensitivity comparison: Wasatch Raman spectrometer vs competitive f/4 spectrometer

This increased sensitivity allows you to significantly improve the limit of detection (LoD) of your experiment or instrument. The graph below shows the WP-830-C LoD for isopropanol for a SNR of 3 being 0.13% while for the competitive f/4 unit the LoD is 3.06%. This is >20x improvement of LoD vs the competition, allowing you to see lower concentrations of samples than ever before, without compromising on size or cost.

Limit of detection comparison: Wasatch Raman spectrometer vs competitive f/4 spectrometer

So why settle? Get 20x improvement in LoD and take your measurement capability to the next level.


The holy grail of spectrometer design is collecting all the ‘good’ photons but eliminating all the ‘bad’ stray ones. Why? Well, any off-axis stray light only serves to diminish the quality of the spectral integrity, leading to compromised performance, notably in regards the limit of detection for Raman and fluorescence studies and the optical dynamic range for absorbance.

To minimize the impact of stray light in a compact spectrometer, you can either deploy a low stray light designed optical bench, or apply mechanical or software corrections to a more generic cross Czerny-Turner design. Wasatch started out with high throughput, low stray light and excellent spectral uniformity as a design goal – a goal they are proud to say they successfully reached in all their spectrometers.

Our optical bench, uniquely, is designed with our internally manufactured, patented HD VPH grating at its heart – with transmission at greater than 97% across its full spectral range and low off-axis light, our spectrometers exhibit the full benefits of the design.

To compare the stray light performance for 785 nm and 830 nm excitation wavelength Raman spectrometers from Wasatch Photonics and competitors, we used the following optical set-up. A 900 nm long pass filter is used to block all photons from shorter wavelengths, and transmits all photons from higher wavelengths from a broadband light source. By comparing the spectral response of each spectrometer for ‘lamp on’ and ‘lamp off’ we can determine the amount of stray light in each design when configured for Raman spectroscopy.

A ‘lower bound’ and ‘upper bound’ spectral region is chosen for the analysis. In each case, the lower bound in each case is shown by the vertical black lines in the graph below, and we use the average signal (blue trace) minus background (orange trace) across this bound for the calculation. The upper bound covers 10 nm either side of the maximum signal, and again the average signal minus dark value in this region is used in the calculation. The ratio of the Upper to Lower bound values then determine the % Stray Light in the optical bench.

For the Wasatch Photonics WP-830-C unit the % stray light determined by this method is 0.007% and the % stray light for the competitive f/4 TEC cooled 830 nm Raman device was 50% worse at 0.015%.


Stray light determination: WP-830-C with long pass filter at entrance, full spectrum


Stray light determination: WP-830-C with long pass filter at entrance, blocked spectrum


So why compromise? With lower inherent stray light, Wasatch Photonics Raman spectrometers give you superior Raman performance.


It’s all well and good to provide industry-leading optical performance, but unless the spectrometers can withstand fair usage and environmental changes, then all that performance counts for nothing.

As spectroscopists ourselves, we know that being able to trust the spectroscopic data in different ambient conditions is paramount. Sure, it’s always best practice to calibrate your instrument to provide accurate spectral matching, but the less you need to worry about this the better.

To validate our impressive thermal stability, we placed our WP 785 series spectrometers in our thermal chamber and measured the atomic emission spectrum of a Xe light source as a function of ambient temperature.

When temperature cycled between 0 °C and 40 °C the new WP-series standard (SR) and extended (ER) range Raman spectrometers exhibit a < 0.05 pixel per °C thermal shift, or a total of 2 pixels or less over the range 0°C to 40°C.

This thermal stability is inherent in the opto-mechanical design, as you can see from the graphs below. All detector options – ambient (room temperature operation), regulated (10°C operation) and cooled (-15°C operation) – exhibit very similar results.

In addition to pixel shift, peak symmetry determined by the R2 of the peak is an important factor in spectral and library matching algorithms. The Xe source peak shape suffers limited distortion during thermal cycling, which is another benefit of the robust of opto-mechanical design of the WP-series Raman spectrometer.

Thermal stability of WP 785 Raman spectrometer, uncooled detector


Thermal stability of competitive Raman spectrometer, uncooled detector

For our Ambient and Regulated products, which have 14 μm wide pixels, this data equates to an approximate 25 μm shift over 40°C. The specifications of most f/4 miniature spectrometer vendors discuss shifts significantly greater than this for their products. For example, for a detector with 1024 pixels, each one 25 μm wide, a leading vendor quotes ± 0.06 pixel per °C or a 60 μm shift, i.e., a shift >2x greater than the WP-series model. For an additional vendor with a 2048-pixel model, each pixel 8 μm wide, we measured a 5-pixel shift over 40°C using the same thermal chamber but using an Hg atomic emission source. This equates to 40 μm of lateral movement which is close to 2x worse than the WP 785 Raman spectrometer.

So why compensate? Uniquely, Wasatch Photonics offers superior optical performance in a thermally stable spectrometer, giving you high quality data you can rely on.


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