PbGa2S4Dy3+
A prototype of a small–sized 4.38-5.5 micron laser emitter
As a result of the research, PbGa2S4, a medium-infrared laser material activated by dysprosium ions, was obtained for the first time in the world, its optical and generation properties were studied, and a prototype of a small—sized diode-pumped laser for the treatment of burns and wounds was manufactured. In 2009, U.S. Patent No. 7, 558, 304 B2 was obtained for the laser material of lead thiogallate.
Until 2000, scientists were unable to create mid-IR lasers due to the unexplored fundamental processes of converting the energy of electronic excitations in solid-state materials with rare earth elements. With a decrease in the energy of electronic transitions in rare-earth ions, the probability of multi-phonon nonradiative relaxation increases. As a result of the interaction of electronic transitions with several phonons of the crystal lattice simultaneously, the transition to the lower state is extinguished. The nature and patterns of nonradiative relaxation have been studied for several decades.
The developed nonlinear theory of multiphonon relaxation has shown that its probability depends on the magnitude of the transition energy, the energy of the effective longitudinal optical phonon, the magnitude of the matrix element of the intermultiplet transition, and the cation radius of the crystal lattice.
Based on this theory, PbGa2S4:Dy3+ medium-IR laser crystals were created for the first time in the world.
Until 2000, scientists were unable to create mid-IR lasers due to the unexplored fundamental processes of converting the energy of electronic excitations in solid-state materials with rare earth elements. With a decrease in the energy of electronic transitions in rare-earth ions, the probability of multi-phonon nonradiative relaxation increases. As a result of the interaction of electronic transitions with several phonons of the crystal lattice simultaneously, the transition to the lower state is extinguished. The nature and patterns of nonradiative relaxation have been studied for several decades.
The developed nonlinear theory of multiphonon relaxation has shown that its probability depends on the magnitude of the transition energy, the energy of the effective longitudinal optical phonon, the magnitude of the matrix element of the intermultiplet transition, and the cation radius of the crystal lattice.
Based on this theory, PbGa2S4:Dy3+ medium-IR laser crystals were created for the first time in the world.
Diagram of the energy levels of the Dy3+ ion | the luminescence (red) and generation (blue) spectra of the PbGa2S4:Dy3+ crystal |
Generation was obtained at two transitions of the ion Dy3+ 6H11/2 — 6H13/2 и 6H9/2 — 6H11/2 according to a cascade scheme.
The pumping was carried out with an IAG-Nd3+ laser at a wavelength of 1.38 microns. Measurement of the lifetime of levels 6H9/2, 6H11/2 and 6H13/2 showed that it is equal to 160 microseconds, 2 ms and 5.6 ms. This means that the 6H11/2 — 6H13/2 and 6H9/2 — 6H11/2 laser junctions are self-limited. Generation develops first at the 6H11/2 — 6H13/2 transition, and then with increasing pumping energy at the 6H9/2 — 6H11/2 transition.
The figures showing the luminescence and generation spectra show that generation is achieved simultaneously on six lines.: three in the range of 4.38–4.7 microns and three in the range of 5.2–5.5 microns.
A pulsed and continuous generation mode is obtained. The pulse energy was 30 MJ with a differential efficiency of 8%. The duration of the generation pulses reached 1.5 ms. A prototype of a medium-IR laser with generation from 4.38–5.5 microns on a PbGa2S4 crystal activated by dysprosium ions.
The PbGa2S4:Dy3+ laser material was highly appreciated by the world scientific community, was noted in the article Fifty years of advances in solid-state laser materials, G. Boulon, Optical materials 34 (2012), 499-512, and was among the world's best achievements.
The pumping was carried out with an IAG-Nd3+ laser at a wavelength of 1.38 microns. Measurement of the lifetime of levels 6H9/2, 6H11/2 and 6H13/2 showed that it is equal to 160 microseconds, 2 ms and 5.6 ms. This means that the 6H11/2 — 6H13/2 and 6H9/2 — 6H11/2 laser junctions are self-limited. Generation develops first at the 6H11/2 — 6H13/2 transition, and then with increasing pumping energy at the 6H9/2 — 6H11/2 transition.
The figures showing the luminescence and generation spectra show that generation is achieved simultaneously on six lines.: three in the range of 4.38–4.7 microns and three in the range of 5.2–5.5 microns.
A pulsed and continuous generation mode is obtained. The pulse energy was 30 MJ with a differential efficiency of 8%. The duration of the generation pulses reached 1.5 ms. A prototype of a medium-IR laser with generation from 4.38–5.5 microns on a PbGa2S4 crystal activated by dysprosium ions.
The PbGa2S4:Dy3+ laser material was highly appreciated by the world scientific community, was noted in the article Fifty years of advances in solid-state laser materials, G. Boulon, Optical materials 34 (2012), 499-512, and was among the world's best achievements.
Picture 15 (a, b). Photographs of experimental soft tissue wounds in rats exposed to laser radiation in the wavelength range of 4.38–5.5 microns with a duration of 6 minutes | Picture 16 (c, d). Photographs of experimental soft tissue wounds in rats during the natural healing process on days 3 (c) and 17 |
Together with the staff of the Medical University, we investigated the dynamics of the microbicidal activity of neutrophil granulocytes in animals with soft tissue wounds using the created prototype of laser radiation.
All the animals were divided into three groups. The first group was a control group. In the second group of animals, the wound surface was irradiated with a laser for 4 minutes daily with an interval of 24 hours for 14 days (Picture 15 a. b). In the third group, under the same conditions, the duration of exposure was 6 minutes.
The material was collected before the start of the experiment, as well as on the 1st, 4th, 7th and 14th days. Blood smears and exudate prints were stained for Pigarevsky cationic protein, and myeloperoxidase activity was determined by Sat. It was found that during the natural course of the wound process, complete repair did not occur in the rats of the control group by the 17th day of the experiment, as evidenced by the presence of visually detectable skin defects (picture c, d). Irradiation of an experimental rat soft tissue wound for 4 or 6 minutes over 8 days has a pronounced activating effect on the oxygen-dependent and oxygen-independent microbicidal systems of neutrophil granulocytes (NG), which leads to a multiple acceleration of reparative processes in the wound (Picture 15 a, b). The area of the rat wound during the natural healing process decreased by 17 days 8.5%, and when irradiated with a laser for 8 days — by 76.5%. Given the time difference during these experiments, it can be argued that the healing rate when wounds are irradiated with a medium-IR laser is 20 times faster than the rate of the natural healing process.
All the animals were divided into three groups. The first group was a control group. In the second group of animals, the wound surface was irradiated with a laser for 4 minutes daily with an interval of 24 hours for 14 days (Picture 15 a. b). In the third group, under the same conditions, the duration of exposure was 6 minutes.
The material was collected before the start of the experiment, as well as on the 1st, 4th, 7th and 14th days. Blood smears and exudate prints were stained for Pigarevsky cationic protein, and myeloperoxidase activity was determined by Sat. It was found that during the natural course of the wound process, complete repair did not occur in the rats of the control group by the 17th day of the experiment, as evidenced by the presence of visually detectable skin defects (picture c, d). Irradiation of an experimental rat soft tissue wound for 4 or 6 minutes over 8 days has a pronounced activating effect on the oxygen-dependent and oxygen-independent microbicidal systems of neutrophil granulocytes (NG), which leads to a multiple acceleration of reparative processes in the wound (Picture 15 a, b). The area of the rat wound during the natural healing process decreased by 17 days 8.5%, and when irradiated with a laser for 8 days — by 76.5%. Given the time difference during these experiments, it can be argued that the healing rate when wounds are irradiated with a medium-IR laser is 20 times faster than the rate of the natural healing process.
PbGa2S4:Dy3+
It is of interest in the future to irradiate rat wounds not for 4 or 6 minutes per day, but for a longer time, up to a continuous radiation regime. Increasing the duration of exposure to wounds with medium infrared radiation may further accelerate their healing.
After additional research, this method can be used in various fields of medicine: disaster medicine, military medicine (in mobile or hospital settings), etc., when rapid and effective wound treatment is of paramount importance for preserving the patient's life and health.
In 2016, the laser on the PbGa2S4:Du3+ element was improved. Generation was obtained at three more wavelengths — 2.4, 4.3 and 5.4 microns. These results appeared in the study of other energy transitions in the laser-active PbGa2S4:Dy3+ material associated with the energy levels 6Н9/2 + 6F11/2 or 6Н11/2. A PbGa2S4:Dy3+-based laser was pumped by radiation from an unsynchronized Nd:YAG laser or by radiation from a laser diode corresponding to the absorption peak of PbGa2S4:Dy3+. The PbGa2S4:Dy3+ crystal was placed in a stable optical resonator with mirrors selected according to the required generation wavelength.
After additional research, this method can be used in various fields of medicine: disaster medicine, military medicine (in mobile or hospital settings), etc., when rapid and effective wound treatment is of paramount importance for preserving the patient's life and health.
In 2016, the laser on the PbGa2S4:Du3+ element was improved. Generation was obtained at three more wavelengths — 2.4, 4.3 and 5.4 microns. These results appeared in the study of other energy transitions in the laser-active PbGa2S4:Dy3+ material associated with the energy levels 6Н9/2 + 6F11/2 or 6Н11/2. A PbGa2S4:Dy3+-based laser was pumped by radiation from an unsynchronized Nd:YAG laser or by radiation from a laser diode corresponding to the absorption peak of PbGa2S4:Dy3+. The PbGa2S4:Dy3+ crystal was placed in a stable optical resonator with mirrors selected according to the required generation wavelength.
- T. T. Basiev, M. E. Doroshenko, Yu. V. Orlovskii, V. V. Osiko, A. G. Avanesov, V. V. Badikov, D. V. Badikov, G. S. Shevyrdyaeva. Spectroscopic properties of a new perspective low‑phonon sulfide crystal PbGa2S4:Nd for the development of efficient near‑IR (~1 nm) and mid‑IR (4–5 nm) solid‑state lasers // Abstracts of the 10th Seminar‑Conference “Optics and Spectroscopy of Condensed Media”, Krasnodar, June 6–11, 2004. P. 77.
- T. T. Basiev, M. E. Doroshenko, V. V. Osiko, D. V. Badikov. Mid‑IR laser oscillations in a new low‑phonon PbGa2S4:Dy3+ crystal // OSA Topical Meetings, ASSP‑2005, February 6–9, 2005, paper TuB10, vol. 98 (2005). P. 75–79.
- T. T. Basiev, M. E. Doroshenko, V. V. Osiko, D. V. Badikov. Mid‑IR laser oscillations in a new low‑phonon PbGa2S4:Dy3+ crystal // ICONO/LAT 2005, May 11–15, 2005, paper LThK18.
- Yurii V. Orlovskii, Tasoltan T. Basiev, Konstantin K. Pukhov, Olimkhon K. Alimov, Maxim E. Doroshenko, Marina V. Polyachenkova, Leonid N. Dmitruk, Vyacheslav V. Osiko, Dmitriy V. Badikov, Valeriy V. Badikov, S. B. Mirov. Mid‑IR laser transitions in Nd3+‑doped CaGa2S4, PbGa2S4, and PbCl2 laser crystals // JOSA, 2005.
- J. Sule, H. Jelincova, M. E. Doroshenko, T. T. Basiev, V. V. Osiko, V. V. Badikov and D. V. Badikov. «Dysprosium‑doped PbGa2S4 laser excited by a diode‑pumped Nd:YAG laser» // Optics Letters, 35, 3051–3953 (2010).
- Maxim E. Doroshenko, Tasoltan T. Basiev, Vyacheslav V. Osiko, Valerii V. Badikov, Dmitrii V. Badikov, Helena Jelinkova, Petr Koranda and Jan Sulc. Oscillation properties of a dysprosium‑doped lead thiogallate crystal // Opt. Lett., vol. 34, no. 5, p. 590–592 (2009).
- Helena Jelinkova, Maxim E. Doroshenko, Jan Sulc, Michal Jelinek, Michal Nemec, Tasoltan T. Basiev, Vitaly Komar, Alexander Gerasimenko, Vyacheslav Puzikov, Valerii Badikov, and Dmitri Badikov. 4–5 µm wavelength radiation generated by mid‑IR lasers // TuP.2 (225), 5th EPS‑QEOD EUROPHOTON Conference “Solid State, Fibre, and Waveguide Coherent Light Sources”, Stockholm, Sweden, August 26–31, 2012.
- Jelínková, Helena; Nemec, Michal; Miyagi, Mitsunobu; Iwai, Katsumasa; Takaku, Hiroyuki; Doroshenko, Maxim; Basiev, Tasoltan T.; Badikov, Valerii V.; Badikov, Dmitri V. Dy:PbGa2S4 laser radiation and its delivery by hollow waveguide // Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XII. Edited by Gannot, Israel. Proceedings of the SPIE, volume 8218, pp. 82180R‑82180R‑5 (2012). DOI: 10.1117/12.908113.
- Helena Jelinkova, Maxim Doroshenko, Michal Jelinek, Jan Sulc, Michal Nemec, Vyacheslav Osiko, Valerii Badikov, Dmitrii Badikov. Diode‑pumped dysprosium‑doped‑PbGa2S4 mid‑infrared laser // CLEO/Europe 2013, Solid‑State Lasers, CA POSTER SESSION, CA‑P.30, Sunday, p. 74, May 12, 2013.
- T. T. Basiev, M. E. Doroshenko, Yu. V. Orlovskii, V. V. Osiko, A. G. Avanesov, V. V. Badikov, D. V. Badikov, G. S. Shevyrdyaeva. Spectroscopic properties of a new perspective low‑phonon sulfide crystal PbGa2S4:Nd for the development of efficient near‑IR (~1 nm) and mid‑IR (4–5 nm) solid‑state lasers // Abstracts of the 10th Seminar‑Conference “Optics and Spectroscopy of Condensed Media”, Krasnodar, June 6–11, 2004. P. 77.
- T. T. Basiev, M. E. Doroshenko, V. V. Osiko, D. V. Badikov. Mid‑IR laser oscillations in a new low‑phonon PbGa2S4:Dy3+ crystal // OSA Topical Meetings, ASSP‑2005, February 6–9, 2005, paper TuB10, vol. 98 (2005). P. 75–79.
- T. T. Basiev, M. E. Doroshenko, V. V. Osiko, D. V. Badikov. Mid‑IR laser oscillations in a new low‑phonon PbGa2S4:Dy3+ crystal // ICONO/LAT 2005, May 11–15, 2005, paper LThK18.
- Yurii V. Orlovskii, Tasoltan T. Basiev, Konstantin K. Pukhov, Olimkhon K. Alimov, Maxim E. Doroshenko, Marina V. Polyachenkova, Leonid N. Dmitruk, Vyacheslav V. Osiko, Dmitriy V. Badikov, Valeriy V. Badikov, S. B. Mirov. Mid‑IR laser transitions in Nd3+‑doped CaGa2S4, PbGa2S4, and PbCl2 laser crystals // JOSA, 2005.
- J. Sule, H. Jelincova, M. E. Doroshenko, T. T. Basiev, V. V. Osiko, V. V. Badikov and D. V. Badikov. «Dysprosium‑doped PbGa2S4 laser excited by a diode‑pumped Nd:YAG laser» // Optics Letters, 35, 3051–3953 (2010).
- Maxim E. Doroshenko, Tasoltan T. Basiev, Vyacheslav V. Osiko, Valerii V. Badikov, Dmitrii V. Badikov, Helena Jelinkova, Petr Koranda and Jan Sulc. Oscillation properties of a dysprosium‑doped lead thiogallate crystal // Opt. Lett., vol. 34, no. 5, p. 590–592 (2009).
- Helena Jelinkova, Maxim E. Doroshenko, Jan Sulc, Michal Jelinek, Michal Nemec, Tasoltan T. Basiev, Vitaly Komar, Alexander Gerasimenko, Vyacheslav Puzikov, Valerii Badikov, and Dmitri Badikov. 4–5 µm wavelength radiation generated by mid‑IR lasers // TuP.2 (225), 5th EPS‑QEOD EUROPHOTON Conference “Solid State, Fibre, and Waveguide Coherent Light Sources”, Stockholm, Sweden, August 26–31, 2012.
- Jelínková, Helena; Nemec, Michal; Miyagi, Mitsunobu; Iwai, Katsumasa; Takaku, Hiroyuki; Doroshenko, Maxim; Basiev, Tasoltan T.; Badikov, Valerii V.; Badikov, Dmitri V. Dy:PbGa2S4 laser radiation and its delivery by hollow waveguide // Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XII. Edited by Gannot, Israel. Proceedings of the SPIE, volume 8218, pp. 82180R‑82180R‑5 (2012). DOI: 10.1117/12.908113.
- Helena Jelinkova, Maxim Doroshenko, Michal Jelinek, Jan Sulc, Michal Nemec, Vyacheslav Osiko, Valerii Badikov, Dmitrii Badikov. Diode‑pumped dysprosium‑doped‑PbGa2S4 mid‑infrared laser // CLEO/Europe 2013, Solid‑State Lasers, CA POSTER SESSION, CA‑P.30, Sunday, p. 74, May 12, 2013.
