| 1. |
- Chitica, N, et al.
(författare)
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Fabrication of tunable InP/air-gap Fabry-Perot cavities by selective etching of InGaAs sacrificial layers
- 1999
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Ingår i: Physica scripta. T. - : ROYAL SWEDISH ACAD SCIENCES. - 0281-1847. ; T79, s. 131-134
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Tidskriftsartikel (refereegranskat)abstract
- We report the fabrication of InP/air-gap Fabry-Perot resonant cavities with an improved tunability characteristic achieved through the micromachining of more flexible suspended InP beams. The micromechanical structures are electrostatically actuated. A tuning range of 55 nm is demonstrated for an actuation voltage of 12 V. The low leakage current, of less than 10 µA for a bias of up to 30 V, provides a low actuation power. The tunable air-gap cavities are fabricated by selective wet etching of InGaAs sacrificial layers. An FeCl3 based etchant is used to completely remove the InGaAs material without affecting the thickness of the InP layer. The anisotropy of the etch rate of InGaAs was also investigated and exploited in the micromachining process.
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| 2. |
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| 3. |
- Hjort, Christian, et al.
(författare)
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Holocene glacial history and sea level changes on James Ross Island, Antarctic Peninsula
- 1997
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Ingår i: Journal of Quaternary Science. - 1099-1417. ; 12:4, s. 259-273
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Tidskriftsartikel (refereegranskat)abstract
- A reconstruction of deglaciation and associated sea-level changes on northern James Ross Island, Antarctic Peninsula, based on lithostratigraphical and geomorphological studies, shows that the initial deglaciation of presently ice-free areas occurred slightly before 7400 14C yr BP. Sea-level in connection with the deglaciation was around 30 m a.s.l. A glacier readvance in Brandy Bay, of at least 7 km, with the initial 3 km over land, reached a position off the present coast at ca. 4600 yr BP. The culmination of the advance was of short duration, and by 4300 yr BP the coastal lowlands again were ice-free. A distinct marine level at 16–18 m a.s.l. was contemporaneous with or slightly post-dates the Brandy Bay advance, thus indicating the relative sea-level around 4600–4500 yr BP. Our results from James Ross Island confirm that over large areas in this part of Antarctica the last deglaciation occurred late.
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| 4. |
- Ingolfsson, O., et al.
(författare)
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Antarctic glacial history since the Last Glacial Maximum: an overview of the record on land
- 1998
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Ingår i: Antarctic Science. - 1365-2079. ; 10:3, s. 326-344
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Tidskriftsartikel (refereegranskat)abstract
- This overview examines available circum-Antarctic glacial history archives on land, related to developments after the Last Glacial Maximum (LGM). It considers the glacial-stratigraphic and morphologic records and also biostratigraphical information from moss banks, lake sediments and penguin rookeries, with some reference to relevant glacial marine records. It is concluded that Holocene environmental development in Antarctica differed from that in the Northern Hemisphere. The initial deglaciation of the shelf areas surrounding Antarctica took place before 10 000 14C yrs before present (BP), and was controlled by rising global sea level. This was followed by the deglaciation of some presently ice-free inner shelf and land areas between 10 000 and 8000 yr BP. Continued deglaciation occurred gradually between 8000 yr BP and 5000 yr BP. Mid-Holocene glacial readvances are recorded from various sites around Antarctica. There are strong indications of a circum-Antarctic climate warmer than today 4700-2000 yr BP. The best dated records from the Antarctic Peninsula and coastal Victoria Land suggest climatic optimums there from 4000-3000 yr BP and 3600-2600 yr BP, respectively. Thereafter Neoglacial readvances are recorded. Relatively limited glacial expansions in Antarctica during the past few hundred years correlate with the Little Ice Age in the Northern Hemisphere.
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| 5. |
- Salvi, J, et al.
(författare)
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Piezoelectric shear force detection: A geometry avoiding critical tip tuning fork gluing
- 1998
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Ingår i: REVIEW OF SCIENTIFIC INSTRUMENTS. - : AMER INST PHYSICS. - 0034-6748. ; 69:4, s. 1744-1746
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A technique for controlling the tip-sample distance in near-field optical microscopes is presented. It consists of mechanically exciting a fiber tip inserted without any adhesive between the two prongs of a high Q-piezoelectric tuning fork. The detection
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