The burgeoning field of biomedicine is resulting in an increased demand in laser technology for biomedical applications. The laser industry has responded to meet that demand. Below are a few examples of how laser technology is evolving for biomedical applications.
True UV Flow in Cytometry
Fluorescence detection has been used in cytometry and other biomedical applications. In cytometry, laser beams are used to excite cells tagged with fluorescent probes where their signals can be segmented into different wavelength bands. A recent trend is to use ultraviolet lasers in this process, but it’s posed some challenges such as green noise, cost, and concerns about using high powered lasers on live cells.
One solution that enables true UV flow in cytometry is the use of optically pumped semiconductor laser technology to generate true continuous wave ultraviolet output without green noise, and with adjustable power output (source: “Lasers meet changing demands of biomedical applications,” Coherent, http://www.coherent.com/downloads/BiomedicalApplications_2015.pdf).
The Noble Prize in Chemistry in 2014 went to Eric Betzig, Stefan W. Hell, and William E. Moerner for their pioneering super-resolution microscopy techniques that have finally broken the previously insurmountable diffraction limit. Like cytometry, some optical super-resolution techniques use lasers that excite fluorescence. These techniques are used to prepare temporary states of bright or dark fluorescence.
Changing the power of a laser beam helps to control the extent of the brightening, or bleaching, of fluorescence. Using a series of images and algorithms, each imaged area can be stitched into a larger, high resolution image. These microscopy applications require lasers with low noise, high power, adjustable power, and new wavelengths for photobleaching. Again, optically pumped semiconductor laser technology is well suited for this particular biomedical application.
Yale researchers have recently developed an electrically pumped semiconductor laser that shows great promise in biomedical imaging, photolithography, and other applications. This new laser offers high brightness, on the par of traditional lasers but without their image corruption issues (speckle). While light emitting diodes are commonly used as a light source, they lack the power required by many biomedical applications requiring high speed imaging. This new electrically pumped semiconductor laser could lead to the next generation in biomedical imaging (source: “New Laser Could Significantly Improve Biomedical Imaging,” MED Device Online, http://www.meddeviceonline.com/doc/new-laser-could-significantly-improve-biomedical-imaging-0001).