We evaluate and demonstrate ultra-broadband near-infrared noncollinear optical parametric amplification in two nonlinear crystals,bismuth borate(Bi BO)and yttrium calcium oxyborate(YCOB),which are not commonly used fo...We evaluate and demonstrate ultra-broadband near-infrared noncollinear optical parametric amplification in two nonlinear crystals,bismuth borate(Bi BO)and yttrium calcium oxyborate(YCOB),which are not commonly used for this application.The spectral bandwidth is of the microjoule level;the amplified signal is≥200 nm,capable of supporting sub-10 fs pulses.These results,supported by numerical simulations,show that these crystals have a great potential as nonlinear media in both low-energy,few-cycle systems and high peak power amplifiers for terawatt to petawatt systems based on noncollinear optical parametric chirped pulse amplification(NOPCPA)or a hybrid.展开更多
The yttrium calcium oxyborate crystal(YCa_(4)O(BO_(3))_(3),YCOB)has been actively studied for hightemperature piezoelectric sensing applications.In this work,the stability of electric properties of YCOB crystal anneal...The yttrium calcium oxyborate crystal(YCa_(4)O(BO_(3))_(3),YCOB)has been actively studied for hightemperature piezoelectric sensing applications.In this work,the stability of electric properties of YCOB crystal annealed in critical conditions(high-temperatures of 900-1100℃ with a low oxygen partial pressure of 4×10^(-6) atm for 24 h)was investigated and the recovery mechanism for the electrical resisitivity,dielectric permittivity and dielectric loss were studied,taking advantage of the X-ray photoelectron spectra and the first principle calculations.The electrical resistivity of the annealed YCOB crystal was slightly decreased when compared to the pristine counterpart,being(2-5)×10^(7) Ω·cm at 850C.The dielectric permittivity and dielectric loss were found to increase after annealing,showing recoverable behaviours after thermal treatment above 650℃ in air.The calculated vacancy formation energy indicates that the oxygen vacancy is the dominant defects in YCOB.The formation of oxygen vacancy weakens the chemical bonding strength between B(Ca or Y)and O atoms,introduces extra donor levels in the band gap,which excites the electrons to conduction band more easily thus enhances the electrical conductivity and dielectric loss.The recovered electrical properties are believed to be associated with the reduced vacancy defects at elevated temperatures in air.展开更多
In this Letter,we realized the phonon-assisted Q-switched laser operation in Yb:YCOB crystal.Differing from previous laser wavelengths below 1.1μm,we extended the wavelength to 1130 nm by amplifying multiphonon-assis...In this Letter,we realized the phonon-assisted Q-switched laser operation in Yb:YCOB crystal.Differing from previous laser wavelengths below 1.1μm,we extended the wavelength to 1130 nm by amplifying multiphonon-assisted electronic transitions.At a repetition rate of 0.1 k Hz,the laser output power was 82 m W with a pulse width of 466.1 ns,corresponding to a high peak power of 1.76 k W and a single pulse energy of 0.82 m J,respectively.To the best of our knowledge,this represents the highest pulse energy among all Yb^(3+)-doped crystal lasers at the wavelength beyond 1.1μm.Such a large pulse energy could be explained by the laser rate-equation theory.These results indicated that the electron-phonon coupling effect not only extends the lasing wavelengths but also enables a fast temporal response to support nanosecond,picosecond,even femtosecond pulse laser operation.展开更多
基金the European Union’s Horizon 2020 research and innovation program under grant agreement No.871124(Laserlab-Europe)the Euratom research and training program 2014–2018 under grant agreement No.633053+1 种基金the Fundacao para a Ciencia e a Tecnologia(FCT,Lisboa)under grants Nos.PD/BD/114327/2016,PD/BD/135177/2017,PD/BD/135222/2017 and PINFRA/22124/2016the framework of the Advanced Program in Plasma Science and Engineering(APPLAu SE,sponsored by FCT under grant No.PD/00505/2012)at Instituto Superior Técnico(IST)。
文摘We evaluate and demonstrate ultra-broadband near-infrared noncollinear optical parametric amplification in two nonlinear crystals,bismuth borate(Bi BO)and yttrium calcium oxyborate(YCOB),which are not commonly used for this application.The spectral bandwidth is of the microjoule level;the amplified signal is≥200 nm,capable of supporting sub-10 fs pulses.These results,supported by numerical simulations,show that these crystals have a great potential as nonlinear media in both low-energy,few-cycle systems and high peak power amplifiers for terawatt to petawatt systems based on noncollinear optical parametric chirped pulse amplification(NOPCPA)or a hybrid.
基金financially supported by the Primary Research&Development Plan of Shandong Province(2017CXGC0413)the National Natural Science Foundation of China(51872165).
文摘The yttrium calcium oxyborate crystal(YCa_(4)O(BO_(3))_(3),YCOB)has been actively studied for hightemperature piezoelectric sensing applications.In this work,the stability of electric properties of YCOB crystal annealed in critical conditions(high-temperatures of 900-1100℃ with a low oxygen partial pressure of 4×10^(-6) atm for 24 h)was investigated and the recovery mechanism for the electrical resisitivity,dielectric permittivity and dielectric loss were studied,taking advantage of the X-ray photoelectron spectra and the first principle calculations.The electrical resistivity of the annealed YCOB crystal was slightly decreased when compared to the pristine counterpart,being(2-5)×10^(7) Ω·cm at 850C.The dielectric permittivity and dielectric loss were found to increase after annealing,showing recoverable behaviours after thermal treatment above 650℃ in air.The calculated vacancy formation energy indicates that the oxygen vacancy is the dominant defects in YCOB.The formation of oxygen vacancy weakens the chemical bonding strength between B(Ca or Y)and O atoms,introduces extra donor levels in the band gap,which excites the electrons to conduction band more easily thus enhances the electrical conductivity and dielectric loss.The recovered electrical properties are believed to be associated with the reduced vacancy defects at elevated temperatures in air.
基金the National Natural Science Foundation of China(Nos.52372010,92163207,and 52025021)the National Key Research and Development Program of China(Nos.2021YFA0717800 and 2021YFB3601504)。
文摘In this Letter,we realized the phonon-assisted Q-switched laser operation in Yb:YCOB crystal.Differing from previous laser wavelengths below 1.1μm,we extended the wavelength to 1130 nm by amplifying multiphonon-assisted electronic transitions.At a repetition rate of 0.1 k Hz,the laser output power was 82 m W with a pulse width of 466.1 ns,corresponding to a high peak power of 1.76 k W and a single pulse energy of 0.82 m J,respectively.To the best of our knowledge,this represents the highest pulse energy among all Yb^(3+)-doped crystal lasers at the wavelength beyond 1.1μm.Such a large pulse energy could be explained by the laser rate-equation theory.These results indicated that the electron-phonon coupling effect not only extends the lasing wavelengths but also enables a fast temporal response to support nanosecond,picosecond,even femtosecond pulse laser operation.
