Compact UV Spectrometer: Now Just 20mm in Length!

Hamamatsu Photonics Introduces UV Model of 'Micro' Spectrometer Series

Hamamatsu Photonics has recently unveiled a new addition to its 'micro' spectrometer series - the C16767MA UV model. This spectrometer offers sensitivity across the range of 190 to 440nm, with a typical resolution of 5.5nm (FWHM, equivalent to ±2.25nm to 50%).

The C16767MA boasts compact dimensions, measuring at 20.1 x 12.5 x 10.1mm, and weighs only 5g. These vital statistics make it an ideal choice for various applications, including water quality monitors. Hamamatsu Photonics explains that the spectrometer can be used to analyze the content of multiple types of pollutants in water through absorption spectrophotometry. It has shown excellent results in measuring nitrite, nitric acid, and biochemical oxygen demand levels. Additionally, when measuring anthracene, the C16767MA has achieved comparable results to those obtained from a benchtop spectrophotometer.

Prior to the C16767MA, previous spectrometers in the micro series were sensitive to UV, but their image sensor sensitivity would gradually decrease when exposed to incident UV. To address this issue, Hamamatsu Photonics made improvements to the image sensor photosensitive area, enhancing its resistance to UV light. They also optimized the shape of the diffraction grating, resulting in improved spectral resolution by shrinking the groove spacing to approximately 500nm. Furthermore, to prevent stray light from affecting the image sensor, a silicon nitride thin film was applied using the company's unique in-house opto-semiconductor device manufacturing technology.

The C16767MA will be showcased at Photon Fair 2023, a three-day in-house exhibition held at Act City Hamamatsu, starting on Thursday, November 16th. Hamamatsu Photonics has chosen to keep further details about the C16767MA under wraps until the exhibition. However, insights into how this device works can potentially be gleaned from the company's earlier C12666MA spectrometer, which shares a similar external appearance and operates within the visible light range of 340 to 780nm.

The C12666MA spectrometer features a slit micromachined into the back of an image sensor die, allowing light to pass through. The light is then reflected back to the sensor by a reflective wavelength-separating 'blazed' diffraction grating, which is manufactured using nano-imprint forming technology. Interfacing with the C12666MA is comparable to interfacing with a video camera IC, requiring power (5V 30mW) and a collection of timing signals. It outputs a video signal that needs to be interpreted externally.