1 June 2020
Kyoto launches compact surface-mounted two-tone photodiode with 400-1700nm wavelength range
Japan’s Kyoto Semiconductor Co Ltd has announced the development of the KP-2 Two-tone Photodiode KPMC29, with a silicon photodiode (sensitive to short wavelengths) and an indium gallium arsenide (InGaAs) photodiode (sensitive to longer wavelengths) giving photosensitivity for a wide range of wavelengths (400-1700nm) layered along the same light axis.
To make the KP-2 two-tone photodiode smaller, the InGaAs photodiodes were laid down in pits arranged on the base for the silicon photodiodes, which ordinarily allows light to pass through. This allowed for the package height to be as low as possible (patents have been filed).
The broadband sensitivity - together with a smaller package (the industry’s smallest-size class and capable of being surface-mounted) that is 1/8th the volume of older Kyoto Semiconductor products - can be used in healthcare applications including medical biometric monitoring such as pulse oximeters as well as wearable activity monitors. Because it is also possible to independently produce photocurrent signals from the silicon and InGaAs photodiodes, measuring the photocurrent ratio will allow use as a radiation thermometer that can measure temperatures without direct contact with hot object.
Spectroscopic analysis technology, which allows for the identification of objects and their characteristics without needing direct contact with those objects (by reflecting light of those objects and measuring the degrees of transmission and reflection), is increasingly needed in a wide range of fields, including medicine, production and security. Spectroscopic analysis relies on two factors for successful use in identifying a wide range of objects: a wider range of wavelengths for the source wavelengths, and a wider range of sensitivity for those wavelengths with the photodiode end. There is also a need for smaller products, compared with existing corded-lead products, for use with medical equipment or wearable devices that can be worn directly on the human body. Development was therefore undertaken to meet these product needs.
Samples of the new KP-2 Two-tone Photodiode KPMC29 will be available from 31 August. Mass production orders will begin on 1 April 2021.