19 research outputs found
Multicascade-linked synthetic wavelength digital holography using an optical-comb-referenced frequency synthesizer
Digital holography (DH) is a promising method for non-contact surface
topography because the reconstructed phase image can visualize the nanometer
unevenness in a sample. However, the axial range of this method is limited to
the range of the optical wavelength due to the phase wrapping ambiguity.
Although the use of two different wavelengths of light and the resulting
synthetic wavelength, i.e., synthetic wavelength DH, can expand the axial range
up to a few tens of microns, this method is still insufficient for practical
applications. In this article, a tunable external cavity laser diode
phase-locked to an optical frequency comb, namely, an optical-comb-referenced
frequency synthesizer, is effectively used for multiple synthetic wavelengths
within the range of 32 um to 1.20 m. A multiple cascade link of the phase
images among an optical wavelength (= 1.520 um) and 5 different synthetic
wavelengths (= 32.39 um, 99.98 um, 400.0 um, 1003 um, and 4021 um) enables the
shape measurement of a reflective millimeter-sized stepped surface with the
axial resolution of 34 nm. The axial dynamic range, defined as the ratio of the
maximum axial range (= 0.60 m) to the axial resolution (= 34 nm), achieves
1.7*10^8, which is much larger than that of previous synthetic wavelength DH.
Such a wide axial dynamic range capability will further expand the application
field of DH for large objects with meter dimensions.Comment: 19 pages, 7 figure
Development and Performance of Kyoto's X-ray Astronomical SOI pixel (SOIPIX) sensor
We have been developing monolithic active pixel sensors, known as Kyoto's
X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for
next-generation X-ray astronomy satellites. The event trigger output function
implemented in each pixel offers microsecond time resolution and enables
reduction of the non-X-ray background that dominates the high X-ray energy band
above 5--10 keV. A fully depleted SOI with a thick depletion layer and back
illumination offers wide band coverage of 0.3--40 keV. Here, we report recent
progress in the X-ray SOIPIX development. In this study, we achieved an energy
resolution of 300~eV (FWHM) at 6~keV and a read-out noise of 33~e- (rms) in the
frame readout mode, which allows us to clearly resolve Mn-K and
K. Moreover, we produced a fully depleted layer with a thickness of
. The event-driven readout mode has already been successfully
demonstrated.Comment: 7pages, 12figures, SPIE Astronomical Telescopes and Instrumentation
2014, Montreal, Quebec, Canada. appears as Proc. SPIE 9147, Space Telescopes
and Instrumentation 2014: Ultraviolet to Gamma Ra
Single Event Tolerance of X-ray SOI Pixel Sensors
We evaluate the single event tolerance of the X-ray silicon-on-insulator
(SOI) pixel sensor named XRPIX, developed for the future X-ray astronomical
satellite FORCE. In this work, we measure the cross-section of single event
upset (SEU) of the shift register on XRPIX by irradiating heavy ion beams with
linear energy transfer (LET) ranging from 0.022 MeV/(mg/cm2) to 68
MeV/(mg/cm2). From the SEU cross-section curve, the saturation cross-section
and threshold LET are successfully obtained to be and ,
respectively. Using these values, the SEU rate in orbit is estimated to be
0.1 event/year primarily due to the secondary particles induced by
cosmic-ray protons. This SEU rate of the shift register on XRPIX is negligible
in the FORCE orbit.Comment: 9 pages, 5 figures, accepted for publication in JATI
Multicascade-linked synthetic wavelength digital holography using an optical-comb-referenced frequency synthesizer
Digital holography (DH) is a promising method for non-contact surface topography because the reconstructed phase image can visualize the nanometer unevenness in a sample. However, the axial range of this method is limited to the range of the optical wavelength due to the phase wrapping ambiguity. Although the use of two different wavelengths of light and the resulting synthetic wavelength, i.e., synthetic wavelength DH, can expand the axial range up to several hundreds of millimeters, its axial precision does not reach sub-micrometer. In this article, we constructed a tunable external cavity laser diode phase-locked to an optical frequency comb, namely, an optical-comb-referenced frequency synthesizer, enabling us to generate multiple synthetic wavelengths within the range of 32 μm to 1.20 m. A multiple cascade link of the phase images among an optical wavelength ( = 1.520 μm) and 5 different synthetic wavelengths ( = 32.39 μm, 99.98 μm, 400.0 μm, 1003 μm, and 4021 μm) enables the shape measurement of a reflective millimeter-sized stepped surface with the axial resolution of 34 nm. The axial dynamic range, defined as the ratio of the axial range ( = 2.0 mm) to the axial resolution ( = 34 nm), achieves 5.9 × 105, which is larger than that of previous synthetic wavelength DH. Such a wide axial dynamic range capability will further expand the application field of DH for large objects with meter dimensions