Biointegrated microlasers: technologies, applications, and emerging developments
Catriona A. Thomson, Anna Popczyk, Marcel Schubert, Catriona A. Thomson
Abstract
Laser light is one of the greatest and most versatile technologies ever invented. Recent developments in the miniaturization of lasers have opened up the possibility of directly interfacing living biological cells with microscopic lasers. The significantly greater brightness and spectral finesse of such biointegrated microlasers, relative to the fluorescent markers commonly used in biomedical research, have enabled numerous applications centered around cellular barcoding and biochemical and biophysical sensing. It further enables measurements in deeper tissue and with greater distinguishability. Here, we review the current state of this quickly growing field, starting with a brief recapitulation of its origins. We describe the prevalent cavity strategies and material systems used, the procedures for ensuring efficient biointegration of lasers, and the instrumentation developed for rapid analysis of light generated by biointegrated lasers, which requires high-resolution hyperspectral imaging. We discuss how the characteristics of biointegrated microlasers are highly applicable to research requiring multiplexed optical barcoding and sensing of cellular dynamics deep in highly scattering tissue. Finally, we share our vision for the future of this nascent field of biophotonics, list the most important challenges that will need to be addressed, and summarize emerging strategies in related areas that may be of particular benefit to the field of biointegrated microlasers.