Single- and multi-layer micro-scale diffractive lens fabrication for fiber imaging probes with versatile depth-of-field
arxiv(2024)
摘要
Hair-thin optical fiber endoscopes have opened up new paradigms for advanced
imaging applications in vivo. In certain applications, such as optical
coherence tomography (OCT), light-shaping structures may be required on fiber
facets to generate needle-like Bessel beams with large depth-of-field, while in
others shorter depths of field with high lateral resolutions are preferable. In
this paper, we demonstrate a novel method to fabricate light-shaping structures
on optical fibres, achieved via bonding encapsulated planar diffractive lenses
onto fiber facets. Diffractive metallic structures have the advantages of being
simple to design, fabricate and transfer, and our encapsulation approach is
scalable to multi-layer stacks. As a demonstration, we design and transfer a
Fresnel zone plate and a diffractive axicon onto fiber facets, and show that
the latter device generates a needle-like Bessel beam with 350 mu m focal
depth. We also evaluate the imaging performance of both devices and show that
the axicon fiber is able to maintain focussed images of a USAF resolution
target over a 150 mu m distance. Finally, we fabricate a two-layer stack of
Fresnel zone plates on a fiber and characterise the modified beam profile and
demonstrate good imaging performance. We anticipate our fabrication approach
could enable multi-functional complex optical structures (e.g. using
plasmonics, polarization control) to be integrated onto fibers for ultra-thin
advanced imaging and sensing.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要