Laser-based holographic techniques continue to grow into commercial markets, used in the production of holographic optical elements (HOEs), for image projection in virtual reality (VR) and augmented reality (AR) devices as well as in white-light analog holography for the generation of ultra-realistic full-color replicas of three-dimensional objects such as museum artefacts. These rapidly developing holographic techniques and holography-based technologies require reliable light sources at multiple wavelengths simultaneously, often in the same optical path. The individual laser performance requirements for holography applications are met by commercially available, extremely reliable, single-frequency or single-longitudinal-mode (SLM) lasers in the visible spectrum with long coherence length, excellent wavelength stability and accuracy, and high, stable output powers. However, the optical alignment and beam combining necessary in multi-wavelength systems can be technically challenging and time consuming. Elaborate assembly and constant maintenance can divert valuable resources away from the more fundamental work necessary to improve quality of the holograms and HOEs. The aim is to develop a laser combiner that provides the necessary performance per laser line with robust beam alignment stability during exposure, and repeatability between exposures, which requires strict control of opto-mechanical component design and thermal management. The performance of a laser combiner, which integrates up to four laser lines with up to 1.5 W of optical power per laser, collinearly aligned with high precision position overlap, angular overlap, and beam pointing stability, and repeatability over long periods of time, is evaluated in this paper. This laser combiner includes the laser sources, control electronics, and beam combining optics and is designed to be easily transportable, providing the ideal combined laser solution to facilitate advancements of holographic techniques.
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.
Conventional fluorescence-based bio-instrumentation equipment typically uses multiple individual lasers combined through optical elements into one beam or an optical fiber. The systems can become bulky, costly to manufacture, and challenging to keep aligned. An extremely compact, permanently aligned, and service-free multi-line laser device can reduce the size and cost of these systems for fluorescence-based research. Removing the complexity of integrating individual lasers with a multi-line solution makes the techniques more cost-efficient, user-friendly, and accessible for all levels of researchers. Here we demonstrate how multi-line lasers are integrated into fluorescence-based instrumentation to simplify experiments without compromising the quality of the results. Integrated electronics, software interfacing, and individual control of each laser-line allow for full flexibility to tailor the laser for the exact experimental needs. Applications include fluorescence microscopy (SIM, TIRF, STED), confocal microscopy, flow cytometry, and combined techniques in research laboratory environments. The Cobolt Skyra multi-line laser is an extremely compact laser device (14.4 cm x 7.0 cm x 3.8 cm) with up to 4 laser lines in one permanently aligned output beam. All optical elements are assembled onto one ultra-stable platform, using patented HTCure™ technology developed by Cobolt, with high precision and permanent alignment. In addition, the multi-line laser can be customized with any combination of more than 14 colors, ranging from 405nm to 660nm, as well as fiber coupling.