Hans Willem Van Kesteren

Tidal breathing FeNO measurements: A new algorithm

International guidelines recommend measuring fractional exhaled nitric oxide (FeNO) during a single slow exhalation with a constant flow of 50 ml/sec. We developed a new algorithm to compute FeNO at 50 ml/sec from tidal breathing measurements. The main objective is to assess the correlation and agreement of this algorithm with the conventional single breath FeNO measurements.

An Integrated Magneto-Optical Sliding Head for First Surface Laser Pulsed Magnetic Field Modulation Magneto-Optical-Recording

A sliding head with integrated focusing lens and magnetic field modulation coil has been designed and manufactured. The component can be used for high data rate, first surface magneto optical recording with a NA=0.85 and λ=400 nm. A coil is integrated into the air bearing surface of a slider to maintain a head-disk distance of around 1 µm. It can generate at least a 200 MHz modulated magnetic field of 15 kA/m fieldstrength. We have tested the coil, slider performance and two stage tracking by using a flat 0.6 mm thick slider.

First-Surface Far Field Magneto-Optical Recording

Magnetic AMplifying Magneto Optical System (MAMMOS) is a promising technology for high storage densities. However, the laser power margin for correct readout is quite small. Based on the understanding of the readout process, recording and readout methods have been developed and tested to improve this margin. First results show that the increased margin allows correct readout of bit lengths as short as 75 nm, which corresponds to an increase in storage density by a factor 1.5 compared to conventional MAMMOS. No changes to the light path or the disk are required. Finally, we measured the rise time of the MAMMOS signal using a fast detector. The result shows that for a numerical aperture (NA)=0.85 and λ=405 nm MAMMOS is capable of data rates around 100 Mb/s.

Blue Zero-Field Magnetic Amplifying Magneto-Optical System (MAMMOS) Recording

We present results of first-surface blue zero-field magnetic amplifying magneto-optical system (MAMMOS) recording of isolated marks of 60 nm and a single tone carrier of 90 nm. The signals are recorded by laser-pulsed magnetic field modulation using a blue laser, a recording head with numerical aperture (NA) = 0.7 with integrated thin film coil and a free working distance of 12 µm from the disc. The media are covered with a 3 µm thin cover layer to prevent heating induced contamination of the optics.

Write Strategies for Improved Readout in RF-Magnetic AMplifying Magneto-Optical System

A promising approach to realize high capacity optical data storage is the use of domain expansion (DomEx) techniques like magnetic amplifying magneto optical system (MAMMOS). However, experiments show that correct readout of long mark domains (multiple bits) is critical and often even impossible, which means that the performance as a (random) data storage technology would be severely limited. Based on a detailed understanding of the MAMMOS readout process, these experimental results are explained and show excellent agreement with numerical simulations: the cause of the readout problems is a decrease in stray field in the centre of long magnetic domains. To solve this problem, write strategies can be applied, where small spaces with opposite magnetization direction are inserted at appropriate locations in each (long) mark domain. From the experimental and simulation results it is clear that this strongly improves the random data readout performance.