In this work,we demonstrate the phonon-assisted vibronic lasing of a Yb-doped sesquioxide Yb:LuScO_(3)crystal.The electron–phonon coupling process was analyzed and the Huang-Rhys factor S was calculated to be 0.75 as...In this work,we demonstrate the phonon-assisted vibronic lasing of a Yb-doped sesquioxide Yb:LuScO_(3)crystal.The electron–phonon coupling process was analyzed and the Huang-Rhys factor S was calculated to be 0.75 associated with the fluorescence spectrum at room temperature.By a rational cavity design to suppress lasing below 1100 nm,a continuously spectral tunability from 1121 to 1136 nm was realized in a Yb:LuScO_(3)laser,which represents the longest achievable wavelength in the Yb-doped sesquioxide lasers.Moreover,the Raman spectrum indicated that the Egphonon mode with a frequency of 472 cm^(-1)was mainly devoted to the phonon-assisted transition process.This work broadens the achievable laser spectrum of Yb-doped sesquioxide,and suggests that the multiphonon–electron coupling strategy should be universal for other laser materials.展开更多
Since the first invention of the laser in 1960,direct lasing outside the fluorescence spectrum is deemed impossible owing to the“zero-gain”cross-section.However,when electron-phonon coupling meets laser oscillation,...Since the first invention of the laser in 1960,direct lasing outside the fluorescence spectrum is deemed impossible owing to the“zero-gain”cross-section.However,when electron-phonon coupling meets laser oscillation,an energy modulation by the quantized phonon can tailor the electronic transitions,thus directly creating some unprecedented lasers with extended wavelengths by phonon engineering.Here,we demonstrate a broadband lasing(1000-1280 nm)in a Yb-doped La_(2)CaB_(10)O_(19)(Yb:LCB)crystal,far beyond its spontaneous fluorescence spectrum.Numerical calculations and in situ Raman verify that such a substantial laser emission is devoted to the multiphonon coupling to lattice vibrations of a dangling“quasi-free-oxygen”site,with the increasing phonon numbers step-by-step(n=1–6).This new structural motif provides more alternative candidates with strong-coupling laser materials.Moreover,the quantitative relations between phonon density distribution and laser wavelength extension are discussed.These results give rise to the search for on-demand lasers in the darkness and pave a reliable guideline to study those intriguing electron-phonon-photon coupled systems for integrated photonic applications.展开更多
Praseodymium-ion-doped gain materials have the superiority of lasing at various visible wavelengths directly.Simple and compact visible lasers are booming with the development of blue laser diodes in recent years.In t...Praseodymium-ion-doped gain materials have the superiority of lasing at various visible wavelengths directly.Simple and compact visible lasers are booming with the development of blue laser diodes in recent years.In this Letter, we demonstrate the watt-level red laser with a single blue laser diode and Pr:YLiF4 crystal.On this basis,the passively Q-switched pulse lasers are obtained with monolayer graphene and Co:ZnO thin film as the Q-switchers in the visible range.展开更多
High-harmonic generation in the ultraviolet region is promising for wireless technology used for communications and sensing. However, small high-order nonlinear coefficients prevent us from obtaining high conversion e...High-harmonic generation in the ultraviolet region is promising for wireless technology used for communications and sensing. However, small high-order nonlinear coefficients prevent us from obtaining high conversion efficiency and functional photonic devices. Here, we show highly efficient ultraviolet harmonic generation extending to the fifth order directly from an epsilon-near-zero indium tin oxide(ITO) film. The real part of the annealed ITO films was designed to reach zero around 1050 nm, matching with the central wavelength of an Yb-based fiber laser, and the internal driving electric field was extremely enhanced. A high energy conversion efficiency of 10-4 and 10-6 for 257.5 nm(fourth-order) and 206 nm(fifth-order) ultraviolet harmonic generation was obtained,which is at least 2 orders of magnitude higher than early reports. Our results demonstrate a new route for overcoming the inefficiency problem and open up the possibilities of compact solid-state high-harmonic generation sources at nanoscale.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2021YFB3601504 and 2021YFA0717800)the National Natural Science Foundation of China(Nos.52002220,92163207,52025021,and 51890863)the Future Plans of Young Scholars at Shandong University。
文摘In this work,we demonstrate the phonon-assisted vibronic lasing of a Yb-doped sesquioxide Yb:LuScO_(3)crystal.The electron–phonon coupling process was analyzed and the Huang-Rhys factor S was calculated to be 0.75 associated with the fluorescence spectrum at room temperature.By a rational cavity design to suppress lasing below 1100 nm,a continuously spectral tunability from 1121 to 1136 nm was realized in a Yb:LuScO_(3)laser,which represents the longest achievable wavelength in the Yb-doped sesquioxide lasers.Moreover,the Raman spectrum indicated that the Egphonon mode with a frequency of 472 cm^(-1)was mainly devoted to the phonon-assisted transition process.This work broadens the achievable laser spectrum of Yb-doped sesquioxide,and suggests that the multiphonon–electron coupling strategy should be universal for other laser materials.
基金supported by the National Key Research and Development Program of China(2021YFB3601504 and 2021YFA0717800)National Natural Science Foundation of China(52025021,92163207,51890862,51890863,and 52002220)Future Plans of Young Scholars at Shandong University.
文摘Since the first invention of the laser in 1960,direct lasing outside the fluorescence spectrum is deemed impossible owing to the“zero-gain”cross-section.However,when electron-phonon coupling meets laser oscillation,an energy modulation by the quantized phonon can tailor the electronic transitions,thus directly creating some unprecedented lasers with extended wavelengths by phonon engineering.Here,we demonstrate a broadband lasing(1000-1280 nm)in a Yb-doped La_(2)CaB_(10)O_(19)(Yb:LCB)crystal,far beyond its spontaneous fluorescence spectrum.Numerical calculations and in situ Raman verify that such a substantial laser emission is devoted to the multiphonon coupling to lattice vibrations of a dangling“quasi-free-oxygen”site,with the increasing phonon numbers step-by-step(n=1–6).This new structural motif provides more alternative candidates with strong-coupling laser materials.Moreover,the quantitative relations between phonon density distribution and laser wavelength extension are discussed.These results give rise to the search for on-demand lasers in the darkness and pave a reliable guideline to study those intriguing electron-phonon-photon coupled systems for integrated photonic applications.
基金supported by the National Key Research and Development Program of China(Nos.2016YFB0701002and 2016YFB1102301)the National Natural Science Foundation of China(NSFC)(Nos.51772173,51632004,51472257,and 51872307)
文摘Praseodymium-ion-doped gain materials have the superiority of lasing at various visible wavelengths directly.Simple and compact visible lasers are booming with the development of blue laser diodes in recent years.In this Letter, we demonstrate the watt-level red laser with a single blue laser diode and Pr:YLiF4 crystal.On this basis,the passively Q-switched pulse lasers are obtained with monolayer graphene and Co:ZnO thin film as the Q-switchers in the visible range.
基金National Natural Science Foundation of China(51632004, 51772173, 51890863, 51902181, 52002220)Taishan Scholar Foundation of Shandong ProvinceFuture Plans of Young Scholars at Shandong University。
文摘High-harmonic generation in the ultraviolet region is promising for wireless technology used for communications and sensing. However, small high-order nonlinear coefficients prevent us from obtaining high conversion efficiency and functional photonic devices. Here, we show highly efficient ultraviolet harmonic generation extending to the fifth order directly from an epsilon-near-zero indium tin oxide(ITO) film. The real part of the annealed ITO films was designed to reach zero around 1050 nm, matching with the central wavelength of an Yb-based fiber laser, and the internal driving electric field was extremely enhanced. A high energy conversion efficiency of 10-4 and 10-6 for 257.5 nm(fourth-order) and 206 nm(fifth-order) ultraviolet harmonic generation was obtained,which is at least 2 orders of magnitude higher than early reports. Our results demonstrate a new route for overcoming the inefficiency problem and open up the possibilities of compact solid-state high-harmonic generation sources at nanoscale.
