. . . . . . "5"^^ . "Axial optical trap stiffness influenced by retro-reflected beam" . "\u0160er\u00FD, Mojm\u00EDr" . "Axial optical trap stiffness influenced by retro-reflected beam"@en . . "RIV/68081731:_____/07:00086311" . "5"^^ . . "Li\u0161ka, M." . . "[46536DBFACE8]" . . "Axial optical trap stiffness influenced by retro-reflected beam" . . . . . "9" . "We studied experimentally how the beam retro-re\uFB02ected from a planar interface (microscope slide) in\uFB02uences the axial stiffness of a single beam trap. Since the incident and retro-re\uFB02ected beams interfere, weak intensity maxima and minima form a standing wave superposed on the axial single focused beam intensity envelope. Therefore there exists competition between the single beam trap and the weak standing wave traps. It results in microsphere hops to a new stable position at certain distances of the beam focus from the retro-re\uFB02ecting surface. We analysed the behaviour of two polystyrene spheres of different sensitivities to the weak standing wave (diameters 690 and 820 nm) placed close to surfaces with different re\uFB02ectivities (common glass R = 0.4% and re\uFB02ective coating R = 13%). We used quadrant photodiode placed in a back focal plane of the microscope objective to track the position of the particle trapped in the single beam trap."@en . . "optical tweezers; optical force; colloidal particle; optical trap; standing wave; stiffness measurement; light scattering; refractive index"@en . "4"^^ . . . "Axi\u00E1ln\u00ED tuhost optick\u00E9 pasti ovlivn\u011Bn\u00E1 zp\u011Btn\u011B odra\u017Een\u00FDm svazkem"@cs . . . "1464-4258" . "J\u00E1kl, Petr" . . "GB - Spojen\u00E9 kr\u00E1lovstv\u00ED Velk\u00E9 Brit\u00E1nie a Severn\u00EDho Irska" . "We studied experimentally how the beam retro-re\uFB02ected from a planar interface (microscope slide) in\uFB02uences the axial stiffness of a single beam trap. Since the incident and retro-re\uFB02ected beams interfere, weak intensity maxima and minima form a standing wave superposed on the axial single focused beam intensity envelope. Therefore there exists competition between the single beam trap and the weak standing wave traps. It results in microsphere hops to a new stable position at certain distances of the beam focus from the retro-re\uFB02ecting surface. We analysed the behaviour of two polystyrene spheres of different sensitivities to the weak standing wave (diameters 690 and 820 nm) placed close to surfaces with different re\uFB02ectivities (common glass R = 0.4% and re\uFB02ective coating R = 13%). We used quadrant photodiode placed in a back focal plane of the microscope objective to track the position of the particle trapped in the single beam trap." . "Je\u017Eek, Jan" . "RIV/68081731:_____/07:00086311!RIV08-AV0-68081731" . . "411254" . "8" . . . . . "Axial optical trap stiffness influenced by retro-reflected beam"@en . "S251;S255" . "Journal of Optics A-Pure and Applied Optics" . "Axi\u00E1ln\u00ED tuhost optick\u00E9 pasti ovlivn\u011Bn\u00E1 zp\u011Btn\u011B odra\u017Een\u00FDm svazkem"@cs . "Zem\u00E1nek, Pavel" . "P(LC06007), R, Z(AV0Z20650511)" . . "Experiment\u00E1ln\u011B jsme studovali vliv svazku odra\u017Een\u00E9ho od rovinn\u00E9ho rozhran\u00ED (podlo\u017En\u00EDho skla) na axi\u00E1ln\u00ED tuhost jednosvazkov\u00E9 optick\u00E9 pasti. Jeliko\u017E doch\u00E1z\u00ED k interferenci dopadaj\u00EDc\u00EDho svazku se svazkem odra\u017Een\u00FDm, vytv\u00E1\u0159\u00ED se slab\u00E1 stojat\u00E1 vlna, kter\u00E1 se moduluje na intenzitn\u00ED ob\u00E1lce zaost\u0159en\u00E9ho svazku. Doch\u00E1z\u00ED tedy ke konkuren\u010Dn\u00ED silov\u00E9 interakci mezi stojatou vlnou a jednosvazkovou optickou past\u00ED. V\u00FDsledkem jsou p\u0159eskoky mikrokuli\u010Dky do nov\u00FDch stabiln\u00EDch pozic v ur\u010Dit\u00FDch vzd\u00E1lenostech pasu laserov\u00E9ho svazku od odrazn\u00E9ho povrchu. Analyzovali jsme chov\u00E1n\u00ED dvou typ\u016F \u010D\u00E1stic o r\u016Fzn\u00FDch citlivostech na stojatou vlnu (polom\u011Bry 690 a 820 nm), kter\u00E9 byly um\u00EDst\u011Bn\u00E9 pobl\u00ED\u017E povrchu s rozd\u00EDlnou odrazivost\u00ED (oby\u010Dejn\u00E9 podlo\u017En\u00ED sklo R = 0,4% a sklo s odraznou vrstvou R = 13%). K detekci polohy \u010D\u00E1stice lapen\u00E9 v optick\u00E9 pasti jsme pou\u017Eili kvadrantn\u00ED fotodiodu um\u00EDst\u011Bnou v zadn\u00ED ohniskov\u00E9 rovin\u011B mikroskopov\u00E9ho objektivu."@cs .