On the basis of thermodynamic and kinetic consideration of Ge-O system,high-pressure oxidation(HPO)on Ge was proposed to suppress the GeO desorption during the thermal oxidation and significant improvements of Ge/GeO2...On the basis of thermodynamic and kinetic consideration of Ge-O system,high-pressure oxidation(HPO)on Ge was proposed to suppress the GeO desorption during the thermal oxidation and significant improvements of Ge/GeO2-based gate stacks have been achieved.It is found that the post oxidation annealing at lower temperatures is helpful to passivate the interface defects at the Ge/GeO2 stack generated by the conventional thermal oxidation,while the high-quality GeO2 bulk properties can only be achieved by HPO that grows GeO2 film at high temperatures without the GeO desorption.This paper reviews the advantage of HPO on the formation of Ge/GeO2 stacks in terms of Ge/GeO2 interface and GeO2 bulk properties.展开更多
In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generatio...In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generation in a single GCF was initially explored,and an SC spanning from visible to MIR regions was obtained,with average power of less than 10 W.To increase the output power,we fabricated a 3×1 high-power GCF-based tapered fiber bundle,incoherently combining three channels of the previously mentioned replicas.This yielded a broadband SC spectrum with a maximum average power of 23.1 W and a spectral bandwidth covering 0.73–3.1μm.The obtained spectrum power fluctuation was measured over 1 hour,showing a root mean square value of 0.7%.To the best of our knowledge,this represents the highest power SC from visible to MIR regions obtained in GCFs pumped by 1.55μm high-power pulses.展开更多
The (60 - x)Bi2O3 - xGeO2-30B2O3-10ZnO (x = 5, 10, 20, 30 molar percent) glasses doped with Er^3+ and Er^3+/Yb^3+ were fabricated using the melting method. The thermal stability of the glasses was studied with ...The (60 - x)Bi2O3 - xGeO2-30B2O3-10ZnO (x = 5, 10, 20, 30 molar percent) glasses doped with Er^3+ and Er^3+/Yb^3+ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3+ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^(t)(λ = 2, 4, 6) character for optical transitions. The infrared emission of Er^3+ was measured upon excitation with 970 nm light and the full width at half-maximum (FWHM) was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3+ were enhanced considerably by co-doping Yb^3+ .展开更多
基金The author would like to thank Prof.Akira Toriumi,Prof.Kita Koji,Prof.Kosuke Nagashio,and Dr.Tomonori Nishimura at the University of Tokyo for their continuous support and encouragement,which induced the main results reviewed in this paper.
摘要On the basis of thermodynamic and kinetic consideration of Ge-O system,high-pressure oxidation(HPO)on Ge was proposed to suppress the GeO desorption during the thermal oxidation and significant improvements of Ge/GeO2-based gate stacks have been achieved.It is found that the post oxidation annealing at lower temperatures is helpful to passivate the interface defects at the Ge/GeO2 stack generated by the conventional thermal oxidation,while the high-quality GeO2 bulk properties can only be achieved by HPO that grows GeO2 film at high temperatures without the GeO desorption.This paper reviews the advantage of HPO on the formation of Ge/GeO2 stacks in terms of Ge/GeO2 interface and GeO2 bulk properties.
基金supported by the National Natural Science Foundation of China(Grant Nos.62090065,62205015 and 62275015)the Natural Science Foundation of Ningbo(Grant No.2022J078)the Technology Innovation Center of Infrared Remote Sensing Metrology Technology,State Administration for Market Regulation(Grant No.AKYKF2425)。
摘要In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generation in a single GCF was initially explored,and an SC spanning from visible to MIR regions was obtained,with average power of less than 10 W.To increase the output power,we fabricated a 3×1 high-power GCF-based tapered fiber bundle,incoherently combining three channels of the previously mentioned replicas.This yielded a broadband SC spectrum with a maximum average power of 23.1 W and a spectral bandwidth covering 0.73–3.1μm.The obtained spectrum power fluctuation was measured over 1 hour,showing a root mean square value of 0.7%.To the best of our knowledge,this represents the highest power SC from visible to MIR regions obtained in GCFs pumped by 1.55μm high-power pulses.
摘要The (60 - x)Bi2O3 - xGeO2-30B2O3-10ZnO (x = 5, 10, 20, 30 molar percent) glasses doped with Er^3+ and Er^3+/Yb^3+ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3+ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^(t)(λ = 2, 4, 6) character for optical transitions. The infrared emission of Er^3+ was measured upon excitation with 970 nm light and the full width at half-maximum (FWHM) was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3+ were enhanced considerably by co-doping Yb^3+ .