Self-curable Micro-cavity Dye Laser Medium Capable Of Mechanical Stress Probing

Recently, Mechanically tunable dye lasers were realized, largely attributed to the adoption of liquid crystalline and/or polydimethylsiloxane (PDMS), which were used as the host matrices for dye molecules or substrates of DFB structures, respectively. However, there are some difficulties in the preparation or use of a flexible dye laser medium. Meanwhile, during the mechanically tuning process, it’s necessary to ascertain the relationship between stress and laser wavelength/mode. Consequently, the feasibility of PDMS as an active medium other than substrate was researched, and theoretically, the relationships of stress-laser mode and stress-laser wavelength were deduced in F-P micro-cavity lasers and VCSELs, respectively. What’s more, some feasible experiment schemes were designed based on the deduced formulae in order to probe the stress.Studies have shown, for the first time to our knowledge, the PDMS elastomer is eligible to be an active layer for doping many dyes. Subsequently, a mechanically tunable F-P micro-cavity laser was fabricated, once exerted pressure on it, the laser mode spacing was broadening, as a result, the minimum stress the F-P micro-cavity laser could detect was～0.03MPa with a resolution of～10.4nm/MPa; as for the OVCSEL counterpart, the laser wavelength was blue-shifting while the stress increased, and it turned out that the minimum stress the OVCSEL could probe was as small as～61.2Pa, and the resolution was as high as5.7nm/kPa. Furthermore, to combine the two methods, the stress was detected based on both laser mode spacing and laser wavelength respectively in the same OVCSEL sample, only to find that, when probed the stress by laser wavelength, the resolution was116times as high as the one detected by laser mode spacing.The laser lifetime was also tested in the PM597-doped PDMS film, as a result, the Normalized Photostability (NP) was higher than6373GJ/mol, which is among the highest record ever reported to our knowledge and a fast self-recovery on the laser output in less one hour, attributed to diffusion of dye molecules is observed, indicating a practical durability for such stress probes.