Fig. 2From: Recent developments in photoacoustic imaging and sensing for nondestructive testing and evaluationTypical PA imaging setup for NDT/E [11]. (a): Schematic of OR-PAM imaging setup; (b): Custom-made sample holder. NDF1: neutral density filter 1; NDF2: neutral density filter 2; L1: lens 1; L2: lens 2; OL: objective lens; WT: water tankBack to article page