Continuous-wave Laser on Er,Yb-Codoped Pentaborate Crystal

We report, for the first time to our knowledge, a diode-pumped continuous-wave microchip Er,Yb:YMgB₅O₁₀ laser. The purpose of this work was to study the growth technique, spectroscopic properties and continuous-wave laser performance of Er³⁺,Yb³⁺:YMgB₅O₁₀ novel crystal.

 Absorption and luminescence spectra as well as kinetics of luminescence decay were studied. Ytterbium-erbium energy transfer efficiency was determined. The output characteristics (output power, slope efficiency, laser wavelength) of Er³⁺,Yb³⁺:YMgB₅O₁₀ laser were determined.

Two intensive absorption bands with peaks centered at 937 nm and 976 nm were observed in the absorption spectra at the wavelength near 1 μm. The maximum value of absorption cross-section was determined to be 1.5·10^–20 cm² at 976 nm for polarization E//N_g . A number of narrow lines were observed in the absorption spectra in the 1425–1575 nm spectral range (transition ⁴I_15/2 → ⁴I_13/2 of erbium ions). The lifetime of the upper laser level 4I13/2 of Er3+ ions was determined to be 390 ± 20 μs. The ytterbium-erbium energy transfer efficiency for YMgB₅O₁₀ crystal with 2 at.% of Er³⁺ and 11 at.% for Yb3+ was close to 84 %. The maximal continuous-wave output power of 0.2 W with slope efficiency of 8 % regarding to absorbed pump power was realized at the wavelength of 1570 nm. With the improvement of cavity parameters the output laser performance of the Er,Yb:YMgB₅O₁₀ crystal can be further enhanced.

Taking into account high thermal conductivity of ≈ 6.2 W·m^–1·K^–1, the Er,Yb:YMgB₅O₁₀ crystal can be considered as a good gain medium for 1.5 μm lasers for applications in laser rangefinder and LIDAR systems.

1. Karlsson G., Laurell F., Tellefsen J., Denker B., Galagan B., Osiko V., Sverchkov S. Development and characterization of Yb-Er laser glass for high average power laser diode pumping. Appl. Phys. B., 2002, vol. 75, no. 1, pp. 41–46. DOI: 10.1007/s00340-002-0950-4

2. Taccheo S., Sorbello G., Laporta P., Karlsson G., Laurell F. 230-mW diode-pumped single-frequency Er,Yb laser at 1.5 μm. IEEE Photonics Technology Letters, 2001, vol. 13, no. 1, pp. 19–21. DOI: 10.1109/68.903207

3. Danger T., Huber G., Denker B.I., Galagan B.I., Sverchkov S.E. Diode-pumped cw laser around 1.54 μm using Yb, Er-doped silico-boro-phosphat glass in Conference on Lasers and Electro-Optics, D. Scifres and A. Weiner, eds., Optical Society of America, 1998, paper CTuM71.

4. Burns P., Dawes J., Dekker P., Pipper J., Jiang H., Wang J. Optimization of Er,Yb:YCOB for cw laser operation. IEEE J. Quantum Electron., 2004, vol. 40, no. 11, pp. 1575–1582. DOI: 10.1109/JQE.2004.834935

5. Huang J., Chen Y., Lin Y., Gong X., Luo Z., Huang Y. High efficient 1.56 μm laser operation of Czochralski grown Er,Yb:Sr3Y2(BO3)4 crystal. Optics Express, 2008, vol. 16, no. 22, pp. 17243–17248. DOI: 10.1364/OE.16.017243

6. Chen Y., Lin Y., Huang J., Gong X., Luo Z., Huang Y. Enhanced performances of diode-pumped sapphire Er3+:Yb3+:LuAl (BO )sapphire microlaser at 1.5–1.6 μm. Opt. Express, 2015, vol. 23, no.9, pp. 12401–12406. DOI: 10.1364/OE.23.012401

7. Gorbachenya K.N., Deineka R.V., Kisel V.E., Yasukevich A.S., Shekhovtsov A.N., Kosmyna M.B., Kuleshov N.V. Er,Yb:Ca3RE2(BO3)4 (RE=Y, Gd) – Novel 1.5 µm Laser Crystals. Devices and Methods of Measurements, 2019, vol. 10, no. 1, pp. 14–22. DOI: 10.21122/2220-9506-2019-10-1-14-22

8. Kisel V.E., Gorbachenya K.N., Yasukevich A.S., Ivashko A.M., Kuleshov N.V., Maltsev V.V., Leonyuk N.I. Passively Q-switched microchip Er,Yb:YAl3(BO3)4 diode-pumped laser. Opt. Lett., 2012, vol. 37, no. 13, pp. 2745–2747. DOI: 10.1364/OL.37.002745

9. Gorbachenya K.N., Kisel V.E., Yasukevich A.S., Maltsev V.V., Leonyuk N.I., Kuleshov N.V. Eye-safe 1.55 μm passively Q-switched Er,Yb:GdAl3(BO3)4 diodepumped laser. Opt. Lett., 2016, vol. 41, no. 5, pp. 918– 921. DOI: 10.1364/OL.41.000918

10. Mitina D.D., Maltsev V.V., Leonyuk N.I., Gorbachenya K.N., Deineka R.V., Kisel V.E., Yasukevich A.S., Kuleshov N.V. Growth and characterization of RMgB5O10 (R=Y, La, Gd) crystals. Inorg.Mater., 2020, vol. 56, no. 2 (accepted). DOI: 10.1134/S0002337X2002013X

11. Sumida D.S., Fan T.Y. Effect of radiation trapping on fluorescence lifetime and emission cross section measurements in solid-state laser media. Opt. Lett., 1994, vol. 19, no. 17, pp. 343−1345. DOI: 10.1364/OL.19.001343

12. Denker B., Galagan B., Ivleva L., Osiko V., Sverchkov S., Voronina I., Hellstrom J.E., Karlsson G., Laurell F. Luminescent and laser properties of Yb,Er activated GdCa4O(BO3)3 a new crystal for eyesafe 1.5 micrometer lasers. Appl. Phys. B., 2004, vol. 79, no. 5, pp. 577−581. DOI: 10.1007/s00340-004-1605-4