Showing papers by "Xingde Li published in 2004"
TL;DR: A miniature endoscope that is capable of rapid lateral scanning and is suitable for real-time forward-imaging optical coherence tomography (OCT) and operated in the new image acquisition sequence at 6 frames/s is demonstrated.
Abstract: We developed a miniature endoscope that is capable of rapid lateral scanning and is suitable for real-time forward-imaging optical coherence tomography (OCT). The endoscope has an outer diameter of 2.4 mm, consisting of a miniature tubular lead zirconate titanate (PZT) actuator, a single-mode fiber-optic cantilever, and a graded-index lens. Rapid lateral scanning at 2.8 kHz is achieved when the fiber-optic cantilever is resonated with the PZT actuator. This allows OCT imaging to be performed by fast lateral beam scanning followed by slow depth scanning, which is different from the conventional OCT imaging sequence. Real-time OCT imaging with the endoscope operated in the new image acquisition sequence at 6 frames/s is demonstrated.
230 citations
TL;DR: A dispersion-free high-speed scanning optical delay line that is suitable for real-time optical coherence tomography, in particular, when an ultrabroadband light source is used.
Abstract: We describe a dispersion-free high-speed scanning optical delay line that is suitable for real-time optical coherence tomography, in particular, when an ultrabroadband light source is used. The delay line is based on all-reflective optics consisting of two flat and one curved mirrors. We achieve optical path-length scanning by oscillating one of the two flat mirrors with a resonant galvanometer. The delay line is compact and easy to implement. A total scanning depth of 1.50 mm with an 89% duty ratio, a maximal scanning speed of ∼9.1 m/s, and a 4.1-kHz repetition rate has been demonstrated.
70 citations
TL;DR: The approach reported here combines a grating-lens delay line and an extra length of a single-mode optical fiber, enabling full compensation of the dispersion caused by the modulator up to the third order, potentially incorporating dynamic dispersion compensation for the sample during depth scanning.
Abstract: We present an effective approach to manage dispersion compensation for a fiber-optic optical coherence tomography (OCT) imaging system in which an electro-optic (EO) phase modulator or an acousto-optic (AO) frequency modulator is used. To balance both the second and third order dispersion caused by the modulator, two independent optical components would be needed. The approach reported here combines a grating-lens delay line and an extra length of a single-mode optical fiber, enabling full compensation of the dispersion caused by the modulator up to the third order. Theoretical analysis of the proposed dispersion management scheme is provided. Experimental results confirmed the theoretical prediction and an optimal OCT axial resolution offered by the light source was recovered. The proposed method can potentially incorporate dynamic dispersion compensation for the sample during depth scanning.
53 citations
01 Jan 2004
TL;DR: It is shown that an optimal axial resolution offered by the light source can be recovered through the dispersion management, and a sufficient Doppler frequency is achieved by using an electro-optic (EO) phase modulator to perform sensitive heterodyne detection.
Abstract: We present a design of a miniature fiber-optic probe capable of rapid lateral scanning. The miniature probe permits forward-looking optical coherence tomography (OCT) imaging of internal organs in real time. Fast lateral scanning also enables a new real-time image acquisition sequence, potentially permitting real-time focus tracking. To perform sensitive heterodyne detection, a sufficient Doppler frequency is achieved by using an electro-optic (EO) phase modulator. In this paper we describe an effective approach to compensate the dispersion induced by the EO crystal up to the third order. We show that an optimal axial resolution offered by the light source can be recovered through the dispersion management. Preliminary results of real-time OCT imaging of biological tissues with the lateral-priority scanning probe are presented.
4 citations
Proceedings Article•
16 May 2004TL;DR: In this paper, the dispersion of a real-time optical coherent tomography system including a phase modulator was compensated up to the third order by the axial resolution was fully recovered experimentally.
Abstract: The dispersion of a real-time optical coherent tomography system including a phase modulator was compensated up to the third order. The axial resolution was fully recovered experimentally, which matches very well with theoretical predictions.
3 citations
Proceedings Article•
16 May 2004TL;DR: A new lateral-priority image acquisition sequence enabled by the endoscope was demonstrated to achieve forward OCT imaging in real time.
Abstract: We developed a 2.4-mm diameter PZT-actuated endoscope capable of rapid lateral scanning at 1.2 kHz. A new lateral-priority image acquisition sequence enabled by the endoscope was demonstrated to achieve forward OCT imaging in real time.
2 citations
Proceedings Article•
16 May 2004TL;DR: In this article, a 2.4mm diameter PZT-actuated endoscope capable of rapid lateral scanning at 1.2 kHz was developed, and a new lateral-priority image acquisition sequence was demonstrated to achieve forward OCT imaging in real time.
Abstract: We developed a 2.4-mm diameter PZT-actuated endoscope capable of rapid lateral scanning at 1.2 kHz. A new lateral-priority image acquisition sequence enabled by the endoscope was demonstrated to achieve forward OCT imaging in real time
2 citations
TL;DR: A new forward-imaging miniature PZT-actuated endoscope of a 2.4-mm diameter, capable of rapid lateral scanning at 2.2 kHz, was developed and real-time OCT imaging was demonstrated using an image acquisition sequence with lateral priority scanning.
Abstract: We developed a new forward-imaging miniature PZT-actuated endoscope of a 2.4-mm diameter, capable of rapid lateral scanning at 2.4 kHz. Real-time OCT imaging was demonstrated using an image acquisition sequence with lateral priority scanning.
1 citations
TL;DR: It is shown that OCT can monitor the cutaneous wound healing process in diabetic and normal mouse models and the migration of the epithelial layer and the formation of the EpidermalDermal junction can be clearly seen.
Abstract: We show that OCT can monitor the cutaneous wound healing process in diabetic and normal mouse models. The migration of the epithelial layer and the formation of the EpidermalDermal junction can be clearly seen.
1 citations
Proceedings Article•
16 May 2004TL;DR: In this paper, a dispersion-free high-speed scanning optical delay line based on one curved and two flat reflective mirrors is described. Butler et al. used a single curved mirror with a total scanning depth of 1.50 mm and 4.1 kHz repetition rate.
Abstract: We describe a dispersion-free high-speed scanning optical delay line, which is based on one curved and two flat reflective mirrors. A total scanning depth of 1.50 mm and a 4.1 kHz repetition rate is demonstrated