Highly efficient achromatic subdiffraction focusing lens in the near field with large numerical aperture

2021 ◽  
Vol 9 (10) ◽  
pp. 2088
Author(s):  
Jin Chen ◽  
Hongchen Chu ◽  
Yun Lai ◽  
Huanyang Chen ◽  
Weili Song ◽  
...  
Keyword(s):  
Near Field ◽  
Numerical Aperture ◽  
Highly Efficient ◽  
Subdiffraction Focusing ◽  
Focusing Lens

Super-Resolution Readout for Magneto-Optical Disk by Optimizing the Deposition Condition of Non-Magnetic Mask Layer

2001 ◽  
Vol 674 ◽  
Author(s):  
Takayuki Shima ◽  
Johoo Kim ◽  
Hiroshi Fuji ◽  
Nobufumi Atoda ◽  
Junji Tominaga
Keyword(s):  
Silver Oxide ◽  
Near Field ◽  
Numerical Aperture ◽  
Super Resolution ◽  
Laser Wavelength ◽  
Deposition Condition ◽  
Resolution Limit ◽  
Plasma Sputtering ◽  
Mask Layer ◽  
Disk Structure

ABSTRACTSuper-resolution near-field structure (Super-RENS) was prepared by a heliconwave-plasma sputtering method to improve the disk property that is combined with a magneto-optical (MO) recording disk. Antimony and silver-oxide mask layers were prepared by the method and refractive indices were measured. Recording and retrieving of signals beyond the resolution limit (<370 nm) were achieved for both mask cases. Attempts to optimize the disk structure were also made using a conventional sputtering method. The smallest mark size was around 200 nm and the highest carrier-to-noise ratio (CNR) was 30 dB for 300-nm mark and 22 dB for 250-nm, when using a laser wavelength of 780 nm and a numerical aperture of 0.53. We have found that there is a competing super-resolutional mechanism besides Super-RENS that appears when high readout laser power is applied. This mechanism played rather an important role at least in the mark-size range of 200-370 nm.

Laser Micro-Machining Using Near-Field Nano-Optics

2004 ◽  
Author(s):  
Haseung Chung ◽  
Katsuo Kurabayashi ◽  
Suman Das
Keyword(s):  
Data Storage ◽  
Near Field ◽  
Numerical Aperture ◽  
Near Field Optics ◽  
Incident Laser Power ◽  
Scanning Optical Microscopy ◽  
Near Field Effect ◽  
Near Field Scanning ◽  
Feature Resolution ◽  
Sub Wavelength

Solid immersion lenses (SIL) facilitate high numerical aperture (NA) and consequent sub-wavelength diffraction limited focusing in near-field optics based systems. Such systems are in commercial and research use for various applications including near-field scanning optical microscopy, ultra-high density magneto-optic data storage and near-field nanolithography. Here, we present a novel nanomanufacturing method using SIL-based near-field optics for laser-induced sub-micron patterning on silicon wafers. The near-field effect of SILs was investigated by using hemispherical BK7 lenses (n=1.5196, NA=0.9237) to superfocus an incident Q-switched, 532nm Nd:YAG laser beam transmitted through a focusing objective. This optical arrangement achieved a laser-processed feature resolution near the diffraction limit in air. Results of experiments that were conducted at various processing conditions to investigate the effects of varying incident laser power (with average pulse power less than 1W), pulse repetition rate, pulse width, number of pulses and size of SIL on processed feature size and resolution are presented.

Near-field phase-change optical recording over 1.2 numerical aperture

1999 ◽  
Author(s):  
Koichiro Kishima ◽  
Yuji Kuroda ◽  
Kimihiro Saito ◽  
Kiyoshi Osato ◽  
Kenji Yamamoto ◽  
...  
Keyword(s):  
Phase Change ◽  
Near Field ◽  
Numerical Aperture ◽  
Optical Recording ◽  
Field Phase

Multi Layer Disk Design For Near Field Phase-Change Recording

2003 ◽  
Vol 803 ◽  
Author(s):  
Koichiro Kishima ◽  
Isao Ichimura ◽  
Kimihiro Saito ◽  
Kenji Yamamoto ◽  
Atsushi Iida ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Crystal ◽  
Layer Structure ◽  
Near Field ◽  
Numerical Aperture ◽  
High Refractive Index ◽  
Field Phase ◽  
Optical Setup ◽  
Field Recording ◽  
Signal Characteristics

ABSTRACTWe propose multi-layer near-field recording with using inner focus mode. The restricted conditions for multi-layer near-field recording are discussed from the viewpoint of both media structure and optical setup. One solution is presented for dual layer recording with a numerical aperture (NA) of 1.5 and a wavelength of 405 nm as a light source of GaN laser diode.In the proposed layer structure, a Nb2O5 material has been adopted as the intermediate layer because of its high refractive index, n = 2.4, in order to prevent the decrease of beam propagation that corresponds to NA>1. Almost the same signal characteristics can be obtained from both recording layers at the air gap of 40 nm. The adjustment of focusing position and the compensation of spherical aberrations have been implemented by the combination of an expander lens unit and a liquid crystal (LC) panel in the optical setup.

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