According to a publication in Nature Communications, researchers from the United Kingdom are developing a flexible, ultra-lightweight polymer membrane lens that can emit laser energy. These lasers are reliant on organic semiconductors that interact with objects using distributed feedback (DFB) resonators. However, until recently this technology had remained too rigid to put on something like a contact lens. But now, researchers have developed a fabrication process to make membrane-based, substrateless and extremely thin (smaller than 500nm) organic DFB lasers at negligible weight for what the publication calls “excellent mechanical flexibility.”
According to the researchers, these lasers may potentially be used for a number of applications, including barcode-like security tagging, counterfeit bank-note detection and even chemo-sensing for recognizing explosives. Researchers note that individual DFB lasers can be identified by their reflection from a white light source. For detecting banknotes, the study shows that “upon pulsed excitation of the section of the banknote containing the membrane, laser action was readily observed.” In other words, it worked, and it didn’t even burn the test eye in the process.
To study the operation of the laser, the team applied it to an excised cow’s eye and scanned it against a compatible laser implanted into the thumbnail of one of the researchers. The power density used to operate the laser “is well within the maximum permissible exposure for intentional and repeated ocular exposure,” say investigators.
|Karl M, Glackin J, Schubert M, et al. Flexible and ultra-lightweight polymer membrane lasers. Nature Communications. May 1, 2018. www.nature.com/articles/s41467-018-03874-w.pdf. Accessed June 19, 2018.|