Optoelectronic chromatic dispersion in photodiodes: Physics and applications in optical sensing and spectroscopy

We are developing a new class of miniaturized optical sensors based on a groundbreaking technology that we have developed. We have discovered that standard PN-junction photodiodes possess huge effective chromatic dispersion, which we call optoelectronic chromatic dispersion (OED). This profound effect is found in all types of commercial photodiodes and forms the basis for a new type of optical spectrometer that is extremely small and inexpensive, and can cover a very wide spectral range, from the UV to the mid IR. The amount of chromatic dispersion in these mass-produced sub-mm sized devices is many orders of magnitude larger than the highest-known values found in other optical materials. These unique features of the OED-based spectrometer are also suitable as an inexpensive, robust, wearable and implantable device for highly sensitive health monitoring.

It has become increasingly clear that miniaturized spectrometers are crucial for advancing analytical capabilities across various fields, including environmental monitoring, healthcare, and industrial processing, making it possible to conduct real-time, embedded, on-site analysis, and greatly enhancing the efficiency and scope of data collection.

  We have discovered and characterized a huge optoelectronic chromatic dispersion (OED) in widely used commercial photodiodes . We have utilized the significant OED of Ge, InGaAs and Si photodiodes in the range 700nm – 1600nm for high-sensitivity wavelength monitoring and material detection. These devices can give high spectral resolution spectroscopy from the UV to the mid IR.

This project will explore the untapped physics and potential applications of OED in photodiodes.