Microsized Optical Spectrometers and Polarimeter Enabled by Organic Photodetectors

Miniaturized optical spectrometers and polarimeters are critical components for portable and wearable analytical systems, with applications spanning environmental monitoring, health diagnostics, and safety assessments. Traditional approaches, relying on miniaturized optics or arrays of photodetectors with different spectral responses, face fundamental limitations when scaled down to microscale dimensions. In this talk, I will present a new microspectrometer architecture that overcomes these challenges using an optical spacer-integrated photomultiplication-type organic photodetector. This configuration enables bias-tunable spectral response, facilitating the computational reconstruction of incident light spectra from photocurrent measurements acquired under a series of controlled bias voltages. Broadband characterization across the entire visible wavelength regime with sub-5 nm resolution is achieved within a remarkably small device footprint of 0.0004 cm². Proof-of-concept hyperspectral imaging is demonstrated with an 8×8 spectroscopic sensor array. Furthermore, I will discuss how the core design principles of this microspectrometer can be extended to create a miniaturized polarimeter, enabling precise polarization measurements in a similarly compact form factor. These advances open up new possibilities for high-resolution optical sensing in portable and wearable devices, broadening the scope of analytical capabilities in diverse real-world scenarios.