Rohm has developed series production of short-wavelength infrared (SWIR) components in the industry's smallest size class 1608 (1.6 x 0.8 mm) for compact sensor applications (light emitters/receivers) in portable devices, wearables and hearables. Such SWIR components have so far come in through-hole housings, and there are only a few surface-mountable products. Samples of SWIR products based on the new technology have been available since March 2023. In the future, Rohm will support an even wider range of material detection in compact applications, opening up new areas for sensor technology.
SWIR has a longer wavelength than NIR (Near Infrared), offers better penetration of materials and is less disturbed by sunlight, smoke and other particles. It is used to detect substances and their components. The main applications include light sources for determining oxygen saturation in the blood and blood sugar levels, as well as the water and sugar content of fruit and vegetables. OLED panels should soon be used in the healthcare sector and other novel applications.
For the light-emitting side, Rohm is planning a series of ten LEDs with different housing shapes and wavelengths (1050 to 1550 nm). On the receiver side, four photodiode designs in different housings and block sizes are to be offered. To accommodate the properties of different materials, SWIR LEDs will be offered in five wavelengths (1050, 1200, 1300, 1450 and 1550 nm): as a molded type and as a lens variant with narrower emission and higher radiation intensity. This means that ten different combinations are available. SWIR photodiodes show a compromise: the smaller the area for light detection, the faster the reaction speed. A larger area offers higher sensitivity. Rohm plans to offer four models with two different light receiver diameters and two housing types.
