Advances in Light-Sheet Fluorescence Microscopy
Light-sheet fluorescence microscopy (LSM) is now an important imaging technique in the biological sciences. This method can provide rapid volumetric imaging with minimal photo damage. Even though LSM is suited for in-vivo imaging such as endomicroscopy and neural imaging in freely moving animals, translation to miniaturized optical systems has been limited to date.
A paper entitled “Generation of Biaxially Accelerating Static Airy Light-Sheets with 3D-Printed Freeform Micro-Optics” describes how physical limitations can be addressed.
The Abstract from this paper states:
One-dimensional Airy beams allow the generation of thin light-sheets without scanning, simplifying the complex optical arrangements of light-sheet microscopes (LSM) with an extended field-of-view (FOV). However, their uniaxial acceleration limits the maximum numerical aperture of the detection objective in order to keep both the active and inactive axes within the depth-of-field. This problem is particularly pronounced in miniaturized LSM implementations, such as those for endomicroscopy or multi-photon neural imaging in freely-moving animals using head-mounted miniscopes. We propose a new method to generate a static Airy light-sheet with biaxial acceleration, based on a novel phase profile. This light-sheet has the geometry of a spherical shell whose radius of curvature can be designed to match the field curvature of the micro-objective. We present an analytical model for the analysis of the light-sheet parameters and verify it by numerical simulations in the paraxial regime. We also discuss a micro-optical experimental implementation combining gradient-index optics with a 3D-nano-printed, fully refractive phase plate. The results confirm that we are able to match detection curvatures with radii in the 1.5 to 2 mm range.
The experimental setup used to measure the biaxially accelerating beam profiles included two components supplied by GRINTECH:
- A cylindrical gradient-index (GRIN) lens with an effective focal length of 1.4 mm
- A fiber-based collimator
About GRINTECH
GRINTECH is a leading manufacturer of GRadient INdex (GRIN) micro-optic lenses and lens systems. These miniaturized lenses provide extraordinarily good optical performance and flat optical surfaces. (See the Explanation of the physics of GRIN lenses.)
The optical power of GRIN lenses is achieved by a refractive index profile fabricated in glass by a non-toxic, silver-and-lithium-ion-exchange process. These unique rod and cylindrical micro-lenses have typical diameters from 200 µm to 2 mm.
The GRINTECH catalog includes:
- GRIN rods used for fiber and laser diode collimation and beam shaping
- Lenses and assemblies for clinical and industrial endoscopic applications
- Needle imaging assemblies and miniature high-NA objectives for in-vivo endomicroscopy and related accessories
These products are used for medical imaging and biophotonic technology, optical metrology, and sensor technology for applications such as brain imaging and endomicroscopy. In addition, GRINTECH develops, fabricates, and delivers high quality, reliable, custom-made modules and assemblies, tailored to the specific needs of customer applications. These assemblies and subassemblies are often inspired by or based on GRINTECH’s standard products.
To support industrial customers, GRINTECH’s team of optical designers and mechanical engineers design and produce more complex optical sensors, focusing or deflecting modules, imaging assemblies consisting of mechanical housings and mounts, optical fibers, prisms, beam splitters, laser diodes, etc., which are combined with GRIN and other lenses.
Customizations include: fiber type, length, buffer, connector type, prism size, stainless steel tube mounts, angled fiber end face, coatings, design wavelengths, spot or image working distance, spot size and numerical aperture, etc.
For more information or a quotation for GRINTECH products, contact IL Photonics.