Olsson Erik, Gren Per, Sjödahl Mikael
Division of Experimental Mechanics, Luleå University of Technology, SE-97187 Luleå, Sweden.
Appl Opt. 2011 Jun 10;50(17):2551-8. doi: 10.1364/AO.50.002551.
Light absorbing objects embedded in silicone have been imaged using photoacoustic digital holography. The photoacoustic waves were generated using a pulsed Nd:YAG laser, λ=1064 nm, and pulse length=12 ns. When the waves reached the silicone surface, they were measured optically along a line using a scanning laser vibrometer. The acoustic waves were then digitally reconstructed using a holographic algorithm. The laser vibrometer is proven to be sensitive enough to measure the surface velocity due to photoacoustic waves generated from laser pulses with a fluence allowed for human tissue. It is also shown that combining digital holographic reconstructions for different acoustic wavelengths provides images with suppressed noise and improved depth resolution. The objects are imaged at a depth of 16.5 mm with a depth resolution of 0.5 mm.
利用光声数字全息术对嵌入硅树脂中的吸光物体进行了成像。光声波由脉冲Nd:YAG激光产生，波长λ = 1064 nm，脉冲长度 = 12 ns。当波到达硅树脂表面时，使用扫描激光振动计沿一条线进行光学测量。然后使用全息算法对声波进行数字重建。事实证明，激光振动计足够灵敏，能够测量由具有人体组织允许能量密度的激光脉冲产生的光声波引起的表面速度。研究还表明，结合不同声波波长的数字全息重建可以提供噪声抑制和深度分辨率提高的图像。这些物体在16.5 mm深度处成像，深度分辨率为0.5 mm。
