Stable and mechanically tunable vertical-cavity surface-emitting lasers (VCSELs) based on dye doped elastic polymeric thin films

• Pyrromethene dyes doped elastic films as active layers of organic VCSELs.
• Mechanically tunable single mode laser emission from 590 to 690 nm.
• High slope efficiencies with low laser threshold and wide tuning range.
• Under somewhat tough pumping, laser output kept almost unchanged after 1 × 105 pulses.
• Fast self-recovery on laser output depending on the dye molecular structure.

In this work, various pyrromethene dyes were doped into elastic films of polydimethylsiloxane (PDMS) as active layers of organic VCSELs and the laser properties of such PDMS-based VCSELs were systematically investigated. Mechanically tunable laser emission with high slope efficiencies, low threshold and wide tuning range were obtained. By uploading various stress or changing distributed-Bragg reflector (DBR) mirrors, single mode laser emission could be tuned from ∼590 to 690 nm, indicating their potential applications as cost-effective coherent sources on bio-chips. Under the pump energy 10 times higher than the threshold, the laser emission of organic VCSELs remained at its initial level after 1.2 × 105 pulses and a fast self-recovery process on the laser output energy with the elapse of aging time was observed. The differences between the self-recovery rates of various pyrromethene dyes were also discussed.