Hamamatsu News 1 / 2018

Hamamatsu will continue to develop products that meet a variety of needs. The G14237- 512WA InGaAs linear image sensor for Raman spectroscopy is one such example. It is said that 1,064 nm excitation Raman spectrophoto­ metry will make possible the detection and identification of medicine and hazardous sub­ stances that were difficult to be measured by conventional means. Raman spectrophotome­ try, which detects low-level light, requires integration over a long time period. As such, on the G14237-512WA, the cutoff wavelength on the long-wavelength side has been reduced from the standard 1.7 μm to 1.45 μm to suppress dark current. Further, for the high-speed type that is used in foreign object detection and other sorting applications, the G14006-512DE with a cutoff wavelength of 1.9 μm has been added to the product lineup. It is also suitable for numerous appli­ cations including the food and agricultural sectors. Verification Example of acquiring the optical spectrum of water, sake, and beer using a spectrometer equipped with an InGaAs image sensor and measuring the light absorption characteristics based on alcohol content <Measurement system> mini-spectrometer: C11118GA (installed image sensor: InGaAs, 0.9 to 2.55 μm, 256 ch), gain: low, integration time: 12 μsec (integration time adjusted so that the A/D count is 60,000 at reference measurement), light source: halogen, cell: 1 mm thick, <measurement> Hamamatsu Central Research Laboratory Water Wide range spectrum from 1.3 μm to 2.3 μm Spectral changes can be seen in the 1.5 μm to 1.75 μm range due to the differences in the alcohol concentration. Spectral changes can be seen near 1.9 μm due to moisture caused by the differences in the alcohol concentration. With the advancement in food processing technology and globalization of trade, we are able to obtain various types of foods, but at the same time, fraudulent claims of origin, dilution, and other frauds are becoming a problem, and consumers are becoming in­ creasingly concerned about food safety. In light of this situation, the new food indication laws in Japan require the indication of items that are of primary concern to consumers such as allergens and nutritional composition. As a result, there is a growing demand to make component analysis, which was previously performed in laboratories, more available to producers, wholesalers, distributors, retailers, and consumers by making measurements easier and non-destructive. The G11475 to G11478 series are InGaAs linear image sensors that are suitable for near-infrared analysis of foods. They support spectral ranges up to 2.6 μm. This spectral range contains absorp­ tion regions originating from carbohydrates, proteins, and lipids. InGaAs linear image sensors make it possible to perform more accurate measurements and analysis. The wafer production of InGaAs photosensors that have a cutoff wavelength exceeding 1.7 μm is highly difficult, and there are not many manufacturers producing them. Hamamatsu utilizes its unique crystal growth technology to stably produce highly accurate and original InGaAs wafers, and offers a diverse product lineup with different supported wavelengths. Cutoff wavelength: up to 2.6 μm – supports long spectral ranges suitable for foods Second derivative spectrum Second derivative spectrum Second derivative spectrum Wavelength (µm) 1.3 0.03 0.02 0.01 -0.01 -0.02 -0.03 0 1.5 1.7 1.9 2.1 2.3 Wavelength (µm) 1.5 0.005 0.003 -0.001 0.001 1.55 1.6 1.65 1.7 1.75 Wavelength (µm) 1.85 0.03 0.01 -0.03 -0.01 1.87 1.89 1.91 1.93 1.95 Meeting specific component analysis needs G14237-512WA G14006-512DE Sake Beer 17 News 2018 Vol. 1