Infrared LEDs enable facial recognition on laptops

Ams Osram has introduced two infrared LEDs (IREDs) with special primary optics, the SFH 4171S and SFH 4181S, in space-saving packages that enable biometric identification in laptops. While facial recognition is widely used to protect data on smartphones and tables, portable computers are often still password-protected, said the company.

“The two IREDs were developed specifically for 2D facial recognition systems,” said Bianka Schnabel, product manager at ams Osram, in a statement. “The user’s face is illuminated with an infrared light source; an infrared camera records the image, and if the captured image matches the one stored in the system, the device is unlocked. In this case, the security system pays attention to two-dimensional features of the user, such as the distance between the eyes and the length of the bridge of the nose.”

The primary optics of the SFH 4171S and SFH 4181S focus the infrared light into a very narrow beam for high-quality images in infrared camera applications. (Image: Osram)

The IREDs are available in two wavelengths – 850 nanometers (SFH 4171S) and 940 nanometers (SFH 4181S). With the SFH 4171S, the benefit is the high sensitivity of the infrared cameras in this range. The SFH 4181S eliminates the “red glow,” which the human eye perceives as red flickering. Both products are housed in a compact Oslon P1616 package. Even with a lens, the product requires very little installation space, measuring only 1.6 × 1.6 × 1.71 mm, said the company. The small size also enables slim display designs for space savings.

Even with the small size, the two IREDs claim an outstanding optical power of 1150 mW at 1 ampere and a beam intensity of 680 mW/sr. The special primary optics bundle the light at a beam angle of 35°, improving performance values and making it easier for the infrared camera to take high-quality images, according to the company. The product selector guide is here; search by part number.