Visual observation of infrared laser speckle patterns at half their fundamental wavelength

Theodossiou, T; Georgiou, E; Hovhannisyan, V; Yova, D

dc.contributor.author	Theodossiou, T	en
dc.contributor.author	Georgiou, E	en
dc.contributor.author	Hovhannisyan, V	en
dc.contributor.author	Yova, D	en
dc.date.accessioned	2014-03-01T01:17:19Z
dc.date.available	2014-03-01T01:17:19Z
dc.date.issued	2001	en
dc.identifier.issn	0268-8921	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14451
dc.subject	Collagen	en
dc.subject	Corneal disorders	en
dc.subject	Laser speckle	en
dc.subject	Second harmonic generation	en
dc.subject.classification	Engineering, Biomedical	en
dc.subject.classification	Surgery	en
dc.subject.other	collagen type 1	en
dc.subject.other	hyaluronic acid	en
dc.subject.other	article	en
dc.subject.other	cornea	en
dc.subject.other	cornea disease	en
dc.subject.other	eye	en
dc.subject.other	infrared laser	en
dc.subject.other	infrared radiation	en
dc.subject.other	interferometry	en
dc.subject.other	lamb	en
dc.subject.other	laser	en
dc.subject.other	light scattering	en
dc.subject.other	nonlinear system	en
dc.subject.other	observer variation	en
dc.subject.other	priority journal	en
dc.subject.other	Animals	en
dc.subject.other	Cattle	en
dc.subject.other	Collagen	en
dc.subject.other	Cornea	en
dc.subject.other	Lasers	en
dc.title	Visual observation of infrared laser speckle patterns at half their fundamental wavelength	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/PL00011334	en
heal.identifier.secondary	http://dx.doi.org/10.1007/PL00011334	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	In the course of work aimed to examine second harmonic generation in biological macromolecules, it was discovered that 1064 nm pulsed nanosecond infrared laser radiation, after scattering on the optically rough sample surface, was perceived as double the fundamental frequency green speckle pattern by the unaided eye. The threshold of this arresting phenomenon was found to be around 60 mJ/cm(2) on hyaluronic acid potassium salt in dark ambient conditions. This effect is of a second order non-linear nature. After experiments with nearsighted, farsighted and normal vision observers in combination with second harmonic generation experiments on various lamb eye tissues, the effect was mainly attributed to second harmonic generation in the cornea arising from phase interference of the incident infrared radiation. The current work could possibly have implications in the fields of speckle interferometry and biomedicine.	en
heal.publisher	SPRINGER-VERLAG LONDON LTD	en
heal.journalName	Lasers in Medical Science	en
dc.identifier.doi	10.1007/PL00011334	en
dc.identifier.isi	ISI:000167025900005	en
dc.identifier.volume	16	en
dc.identifier.issue	1	en
dc.identifier.spage	34	en
dc.identifier.epage	39	en