Highly efficient, diffraction-limited laser emission from a vertical external-cavity surface-emitting organic laser.

Area of Science:

• Optics and Photonics
• Materials Science
• Organic Electronics

Background:

• Vertical External Cavity Surface-Emitting Lasers (VECSELs) are crucial in various photonic applications.
• Developing cost-effective and efficient solid-state laser gain media remains an active research area.
• Organic materials offer potential for novel laser designs due to their tunable properties.

Purpose of the Study:

• To demonstrate a novel solid-state laser structure using an organic gain medium.
• To investigate the performance characteristics of an organic VECSEL counterpart.
• To explore spectral control and tunability in the developed organic laser system.

Main Methods:

• Fabrication of a plano-concave resonator with a Rhodamine 640 doped poly(methyl methacrylate) film as the gain medium.
• Optical pumping of the gain medium using nanosecond pulsed lasers at 532 nm.
• Characterization of the output beam quality, conversion efficiency, and spectral properties.

Main Results:

• A diffraction-limited beam (M(2)=1) was achieved with a conversion efficiency of 43%.
• Higher peak powers (2 kW) were obtained using shorter pump pulses (0.5 ns).
• The laser spectrum was controlled by the active layer thickness, demonstrating tunability over 20 nm.

Conclusions:

• The developed solid-state organic laser structure is a viable alternative to VECSELs.
• The system exhibits high conversion efficiency and tunable output, suitable for various applications.
• The use of organic gain media offers a promising route for future laser development.