Interference femtosecond laser stamping of micro-grating structures and time-resolved observation of its dynamics

the study of practical and theoretical foundation of credit risk and its coverage

پس از بررسی هر کدام از فاکتورهای نوع صنعت, نوع ضمانت نامه, نرخ بهره , نرخ تورم, ریسک اعتباری کشورها, کارمزد, ریکاوری, gdp, پوشش و وثیقه بر ریسک اعتباری صندوق ضمانت صادرات ایران مشخص گردید که همه فاکتورها به استثنای ریسک اعتباری کشورها و کارمزد بقیه فاکتورها رابطه معناداری با ریسک اعتباری دارند در ضمن نرخ بهره , نرخ تورم, ریکاوری, و نوع صنعت و ریسک کشورها اثر عکس روی ریسک اعتباری داردو پوشش, وثی...

Interference between femtosecond pulses observed via time-resolved spontaneous fluorescence

We study spontaneous fluorescence excited by a series of phase-controlled femtosecond pulses in an inhomogeneously broadened medium containing a frequency comb of sharp spectral holes. We show that evolution of the spontaneous fluorescence on picosecond time scale is sensitive to interference between the excitation pulses and that varying the relative phase between the excitation pulses changes...

Femtosecond time-resolved laser experiments performed in collaboration with Professor

Characterizing femtosecond laser inscribed Bragg grating spectra.

We present numerical modeling based on a combination of the Bidirectional Beam Propagation Method and Finite Element Method that completely describes the wavelength spectra of point by point femtosecond laser inscribed fiber Bragg gratings, showing excellent agreement with experiment. We have investigated the dependence of different spectral parameters such as insertion loss, all dominant cladd...

Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation

Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation K. R. P. Kafka, D. R. Austin, H. Li, A. Yi, J. Cheng, and E. A. Chowdhury Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210, USA Department of Integrated Systems Engineering, The Ohio State University, 1971 Neil Ave Columbus, OH 43210 Harbin Institute ...