Tunable single-mode cw energy-transfer dye laser directly optically pumped by a diode laser

• Published in: Optics and laser technology 2019-12, Vol.120, p.105673, Article 105673
• Main Authors: Stefańska, Danuta, Suski, Marcin, Zygmunt, Anna, Stachera, Justyna, Furmann, Bogusław
• Format: Article
• Language: English
• Subjects: Continuous radiation; Coumarin; Coupling; Diode laser; Dye laser; Dye lasers; Dyes; Energy transfer; Lasers; Lasing; Optical pumping; Output coupling; Semiconductor lasers; Single mode operation; Wave power
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2019.105673

•Energy transfer dye laser cw generation under diode laser optical pumping achieved.•Dye mixture: Coumarin 498/Pyrromethene 556 applied for the first time.•Obtained: broad-band tuning range ca. 530–575 nm, maximum slope efficiency ca. 11%.•Single-mode operation and smooth frequency scanning up to ca. 40 GHz achieved.•Significant improvement expected with application of higher power pump diode laser. Within this work a tunable single-mode continuous wave energy transfer dye laser operation in green-yellow spectral region was achieved under direct optical pumping by an economy-class diode laser at λ = 445 nm. The laser is operated on a binary dye mixture: Coumarin 498 (donor) and Pyrromethene 556 (acceptor); the latter exhibits only negligible absorption at the pump wavelength, and thus its lasing is almost exclusively due to the excitation energy transfer. This binary energy transfer dye mixture was studied for the first time. Basic lasing properties at various acceptor concentrations were examined; donor concentration was fixed at the value optimum for its lasing under the optical pumping conditions applied. For the final acceptor concentration the optimum output coupling was determined for selected wavelengths from the measurements of the output power in variable output coupling scheme. Single-mode operation sufficiently stable for high-resolution spectroscopic applications was also achieved and tested. Further investigations of the energy transfer mechanisms and efficiency in the binary dye mixture applied are in progress and will be reported separately.