Proceedings Article | 17 February 2020
KEYWORDS: Microscopy, Microscopes, Laser applications, Optical alignment, Integrated optics, Argon ion lasers, Laser optics, Flow cytometry, Fiber couplers, Lasers
The integration of multi-color laser excitation into biomedical instrumentation is associated with several challenges which must be overcome to meet the desired performance requirements of the instrument. Multi-color lasers are needed in fluorescence-analysis based applications such as flow cytometry, DNA sequencing, and various types of fluorescence microscopes such as scanning confocal microscopes, TIRF, Light-sheet, SIM, STORM and STED techniques. In many cases, these techniques require capability for excitation of multiple fluorophores and therefore access to several laser lines within the instrument. The advantages of lasers over other light-sources, such as LEDs, for these techniques are high-brightness and wavelength precision. Unfortunately, the inclusion of lasers also introduces complexity in the design. Laser combiners including individual lasers have been integrated with the intention of simplifying the design, as an alternative to traditional multiline gas lasers. This solution, however, is still susceptible to misalignment over time, and can increase the size and cost of the instrument. A compact, permanently aligned, multi-line laser simplifies the integration of multiple laser wavelengths by eliminating the need for in-field alignment and service, reducing manufacturing cost, and allowing for more compact designs. In addition to overcoming the initial design challenges of integrating lasers into bio-instrumentation, a multi-line laser is also an easy-to-upgrade field replacement for previous generations of technology, such as Argon Ion gas lasers. Here we demonstrate how a compact and robust permanently aligned multi-line solid-state laser can be achieved using novel techniques for optical assembly and miniaturization. We also show how the integration of such a multi-line laser can deliver the required optical performance while simplifying the design and enabling commercialization of a new bioimaging technology, and exemplify the integration of this solution as a drop-in replacement for an Argon Ion lasers in existing microscope set-ups.