High Time-Resolved Three-Dimensional Imaging Using Ultrafast Optical Kerr Gate of Bismuth Glass

We have demonstrated the high time-resolved three dimensional (3-D) imaging using a chirped supercontinuum (SC) and an ultrafast optical Kerr gate (OKG) generated with a femtosecond laser, in which a sapphire plate and a Bi₂O₃-B₂O₃-SiO₂ oxide glass (BI glass) were used to generate the chirped SC and the optical Kerr gate, respectively. The experimental results show that the 3-D imaging using BI glass offers better temporal and longitudinal spatial resolution compared with CS₂.

I. Introduction

Time-Resolved imaging based on optical Kerr gate (OKG) has provided an interesting tool for scientific research and various potential applications. This imaging technique was first proposed by Alfano et al., and used to the ballistic optical imaging for objects hidden in scattering media, such as high-pressure diesel sprays and liquid jets in gaseous crossflow [1]–[4]. Combining with a chirped supercontinuum (SC), OKG was also used to realize the simultaneous three dimensional (3-D) imaging [5]–[7]. Moreover, time-resolved imaging based on OKG was an effective method to diagnose various ultrafast phenomena, such as ultrafast fluorescence, laser-produced plasmas and propagation dynamics of laser pulses in a medium [8]–[12].