Isotropic diffraction-limited focusing using a single objective lens.
نویسندگان
چکیده
Focusing a light beam through a lens produces an anisotropic spot elongated along the optical axis, because the light comes from only one side of the focal point. Using the time-reversal concept, we show that isotropic focusing can be realized by placing a mirror after the focal point and shaping the incident beam. This idea is applied to confocal microscopy and brings about a dramatic improvement of the axial resolution.
منابع مشابه
Optical phase conjugation (OPC)-assisted isotropic focusing.
Isotropic optical focusing - the focusing of light with axial confinement that matches its lateral confinement, is important for a broad range of applications. Conventionally, such focusing is achieved by overlapping the focused beams from a pair of opposite-facing microscope objective lenses. However the exacting requirements for the alignment of the objective lenses and the method's relative ...
متن کاملPlanar metal/dielectric single-periodic multilayer ultraviolet flat lens
In 1968, Veselago predicted that a thin film composed of a material with a negative refractive index would act as a flat lens [Sov. Phys. Usp. 10, 509 (1968)]. Hyperbolic metamaterials have been designed that show negative refraction, but the condition of an isotropic refractive index n −1 required to realize a diffraction-limited focus cannot be realized using the hyperbolic dispersion. Here, ...
متن کاملMetalenses at visible wavelengths: Diffraction-limited focusing and subwavelength resolution imaging.
Subwavelength resolution imaging requires high numerical aperture (NA) lenses, which are bulky and expensive. Metasurfaces allow the miniaturization of conventional refractive optics into planar structures. We show that high-aspect-ratio titanium dioxide metasurfaces can be fabricated and designed as metalenses with NA = 0.8. Diffraction-limited focusing is demonstrated at wavelengths of 405, 5...
متن کاملSingle-impulse magnetic focusing of launched cold atoms
We have theoretically investigated the focusing of a launched cloud of cold atoms. Time-dependent spatially-varying magnetic fields are used to impart impulses leading to a three-dimensional focus of the launched cloud. We discuss possible coil arrangements for a new focusing regime: isotropic 3D focusing of atoms with a single magnetic lens. We investigate focusing aberrations and find that, f...
متن کاملFocusing of light beyond the diffraction limit of half the wavelength.
The diffraction limit sets the smallest achievable linewidth at half the wavelength. With a subwavelength plasmonic lens allowing one to reduce the diffraction via an asymmetry and to generate and squeeze the wave functions, an incident light is focused by the aperture to a single line with its width smaller than the limited value in the intermediate zone. The focused fields are capable of prop...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 105 20 شماره
صفحات -
تاریخ انتشار 2010