Endoscopic optical coherence tomography with a focus-adjustable probe

• Published in: Optics letters Vol. 42; no. 20; p. 4040
• Main Authors: Liao, Wenchao, Chen, Tianyuan, Wang, Chengming, Zhang, Wenxin, Peng, Zhangkai, Zhang, Xiao, Ai, Shengnan, Fu, Deyong, Zhou, Tieying, Xue, Ping
• Format: Journal Article
• Language: English
• Published: United States 15.10.2017
• Subjects: Endoscopy; Image Enhancement - methods; Phantoms, Imaging; Tomography, Optical Coherence - methods
• ISSN: 1539-4794
• DOI: 10.1364/OL.42.004040

We present a focus-adjustable endoscopic probe for optical coherence tomography (OCT), which is able to acquire images with different focal planes and overcome depth-of-focus limitations by image fusing. The use of a two-way shape-memory-alloy spring enables the probe to adjust working distance over 1.5 mm, providing a large scanning range with high resolution and no sensitivity loss. Equipped with a homemade hollow-core ultrasonic motor, the probe is capable of performing an unobstructed 360 deg field-of-view distal scanning. Both the axial resolution and the best lateral resolution are ∼4  μm, with a sensitivity of 100.3 dB. Spectral-domain OCT imaging of phantom and biological tissues with the probe is also demonstrated.