Beam propagation method for wide-field nonlinear wave mixing microscope*
Lv Yong-Ganga), Ji Zi-Henga), Yu Wen-Taoa), Shi Ke-Bin†a),b)
       
Schematic diagram of our method. The pump and the Stokes beams (red) irradiate a PS microsphere suspending in water generating the CARS signal (green to pink). Along the direction of propagation, the whole space is uniformly divided into n parts of length d z . In each slice, the CARS signal generation and propagation are considered separately. Specifically, from Z k to Z k +1/2 and from Z k +1/2 to Z k +1, only diffraction is considered. The nonlinear wave mixing signal only generates at the middle (red dotted line) of the slice.