Photonics

1948 KiB

Open AccessReview

Hybrid Photonic Integration on a Polymer Platform

by Ziyang Zhang, David Felipe, Vasilis Katopodis, Panos Groumas, Christos Kouloumentas, Hercules Avramopoulos, Jean-Yves Dupuy, Agnieszka Konczykowska, Alberto Dede, Antonio Beretta, Antonello Vannucci, Giulio Cangini, Raluca Dinu, Detlef Schmidt, Martin Moehrle, Patrick Runge, Jung-Han Choi, Heinz-Gunter Bach, Norbert Grote, Norbert Keil and Martin Schell Show full author list Hide full author list

Photonics 2015, 2(3), 1005-1026; https://doi.org/10.3390/photonics2031005 - 21 Sep 2015

Cited by 52 | Viewed by 10764

Abstract

To fulfill the functionality demands from the fast developing optical networks, a hybrid integration approach allows for combining the advantages of various material platforms. We have established a polymer-based hybrid integration platform (polyboard), which provides flexible optical input/ouptut interfaces (I/Os) that allow robust [...] Read more.

To fulfill the functionality demands from the fast developing optical networks, a hybrid integration approach allows for combining the advantages of various material platforms. We have established a polymer-based hybrid integration platform (polyboard), which provides flexible optical input/ouptut interfaces (I/Os) that allow robust coupling of indium phosphide (InP)-based active components, passive insertion of thin-film-based optical elements, and on-chip attachment of optical fibers. This work reviews the recent progress of our polyboard platform. On the fundamental level, multi-core waveguides and polymer/silicon nitride heterogeneous waveguides have been fabricated, broadening device design possibilities and enabling 3D photonic integration. Furthermore, 40-channel optical line terminals and compact, bi-directional optical network units have been developed as highly functional, low-cost devices for the wavelength division multiplexed passive optical network. On a larger scale, thermo-optic elements, thin-film elements and an InP gain chip have been integrated on the polyboard to realize a colorless, dual-polarization optical 90° hybrid as the frontend of a coherent receiver. For high-end applications, a wavelength tunable 100Gbaud transmitter module has been demonstrated, manifesting the joint contribution from the polyboard technology, high speed polymer electro-optic modulator, InP driver electronics and ceramic electronic interconnects. Full article

(This article belongs to the Special Issue Hybrid and Heterogeneous Technologies in Photonics Integrated Circuits)

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2350 KiB

Open AccessReview

III-V-on-Silicon Photonic Devices for Optical Communication and Sensing

by Gunther Roelkens, Amin Abassi, Paolo Cardile, Utsav Dave, Andreas De Groote, Yannick De Koninck, Sören Dhoore, Xin Fu, Alban Gassenq, Nannicha Hattasan, Qiangsheng Huang, Sulakshna Kumari, Shahram Keyvaninia, Bart Kuyken, Lianyan Li, Pauline Mechet, Muhammad Muneeb, Dorian Sanchez, Haifeng Shao, Thijs Spuesens, Ananth Z. Subramanian, Sarah Uvin, Martijn Tassaert, Kasper Van Gasse, Jochem Verbist, Ruijun Wang, Zhechao Wang, Jing Zhang, Joris Van Campenhout, Xin Yin, Johan Bauwelinck, Geert Morthier, Roel Baets and Dries Van Thourhout Show full author list Hide full author list

Photonics 2015, 2(3), 969-1004; https://doi.org/10.3390/photonics2030969 - 18 Sep 2015

Cited by 125 | Viewed by 23011

Abstract

In the paper, we review our work on heterogeneous III-V-on-silicon photonic components and circuits for applications in optical communication and sensing. We elaborate on the integration strategy and describe a broad range of devices realized on this platform covering a wavelength range from [...] Read more.

In the paper, we review our work on heterogeneous III-V-on-silicon photonic components and circuits for applications in optical communication and sensing. We elaborate on the integration strategy and describe a broad range of devices realized on this platform covering a wavelength range from 850 nm to 3.85 μm. Full article

(This article belongs to the Special Issue Hybrid and Heterogeneous Technologies in Photonics Integrated Circuits)

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695 KiB

Open AccessArticle

Integrated Microwave Photonic Isolators: Theory, Experimental Realization and Application in a Unidirectional Ring Mode-Locked Laser Diode

by Martijn J.R. Heck, Sudharsanan Srinivasan, Michael L. Davenport and John E. Bowers

Photonics 2015, 2(3), 957-968; https://doi.org/10.3390/photonics2030957 - 10 Sep 2015

Cited by 12 | Viewed by 6948

Abstract

A novel integrated microwave photonic isolator is presented. It is based on the timed drive of a pair of optical modulators, which transmit a pulsed or oscillating optical signal with low loss, when driven in phase. A signal in the reverse propagation direction [...] Read more.

A novel integrated microwave photonic isolator is presented. It is based on the timed drive of a pair of optical modulators, which transmit a pulsed or oscillating optical signal with low loss, when driven in phase. A signal in the reverse propagation direction will find the modulators out of phase and, hence, will experience high loss. Optical and microwave isolation ratios were simulated to be in the range up to 10 dB and 20 dB, respectively, using parameters representative for the indium phosphide platform. The experimental realization of this device in the hybrid silicon platform showed microwave isolation in the 9 dB–22 dB range. Furthermore, we present a design study on the use of these isolators inside a ring mode-locked laser cavity. Simulations show that unidirectional operation can be achieved, with a 30–50-dB suppression of the counter propagating mode, at limited driving voltages. The potentially low noise and feedback-insensitive operation of such a laser makes it a very promising candidate for use as on-chip microwave or comb generators. Full article

(This article belongs to the Special Issue Hybrid and Heterogeneous Technologies in Photonics Integrated Circuits)

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573 KiB

Open AccessArticle

Microfiber-Lithium Niobate on Insulator Hybrid Waveguides for Efficient and Reconfigurable Second-Order Optical Nonlinearity on a Chip

by Andrey V. Gorbach and Wei Ding

Photonics 2015, 2(3), 946-956; https://doi.org/10.3390/photonics2030946 - 9 Sep 2015

Cited by 8 | Viewed by 7599

Abstract

We present an optical microfiber-lithium niobate on insulator (MF-LNOI) hybrid waveguide for efficient second-order nonlinear processes. The structure combines the advantages of low-loss fiber and high-nonlinearity waveguide systems. We demonstrate the possibility of phase matching between fundamental and second harmonics in a wide [...] Read more.

We present an optical microfiber-lithium niobate on insulator (MF-LNOI) hybrid waveguide for efficient second-order nonlinear processes. The structure combines the advantages of low-loss fiber and high-nonlinearity waveguide systems. We demonstrate the possibility of phase matching between fundamental and second harmonics in a wide spectral and dimensional range, and efficient second harmonic generation over sub-millimeter propagation distances, both of which are very attractive for high-density on-chip integration. Full article

(This article belongs to the Special Issue Hybrid and Heterogeneous Technologies in Photonics Integrated Circuits)

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790 KiB

Open AccessArticle

Four-Wave Optical Parametric Amplification in a Raman-Active Gas

by Yuichiro Kida and Totaro Imasaka

Photonics 2015, 2(3), 933-945; https://doi.org/10.3390/photonics2030933 - 31 Aug 2015

Cited by 2 | Viewed by 5258

Abstract

Four-wave optical parametric amplification (FWOPA) in a Raman-active medium is experimentally investigated by use of an air-filled hollow fiber. A femtosecond pump pulse shorter than the period of molecular motion excites the coherent molecular motion of the Raman-active molecules during the parametric amplification [...] Read more.

Four-wave optical parametric amplification (FWOPA) in a Raman-active medium is experimentally investigated by use of an air-filled hollow fiber. A femtosecond pump pulse shorter than the period of molecular motion excites the coherent molecular motion of the Raman-active molecules during the parametric amplification of a signal pulse. The excited coherent motion modulates the frequency of the signal pulse during the parametric amplification, and shifts it to lower frequencies. The magnitude of the frequency redshift depends on the pump intensity, resulting in intensity-dependent spectral characteristics that are different from those in the FWOPA induced in a noble-gas-filled hollow fiber. Full article

(This article belongs to the Special Issue Nonlinear Fiber Optics)

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685 KiB

Open AccessArticle

Characteristics of the Current-Controlled Phase Transition of VO₂ Microwires for Hybrid Optoelectronic Devices

by Arash Joushaghani, Junho Jeong, Suzanne Paradis, David Alain, J. Stewart Aitchison and Joyce K.S. Poon

Photonics 2015, 2(3), 916-932; https://doi.org/10.3390/photonics2030916 - 28 Aug 2015

Cited by 12 | Viewed by 5776

Abstract

The optical and electrical characteristics of the insulator-metal phase transition of vanadium dioxide (VO₂) enable the realization of power-efficient, miniaturized hybrid optoelectronic devices. This work studies the current-controlled, two-step insulator-metal phase transition of VO₂ in varying microwire geometries. Geometry-dependent scaling [...] Read more.

The optical and electrical characteristics of the insulator-metal phase transition of vanadium dioxide (VO₂) enable the realization of power-efficient, miniaturized hybrid optoelectronic devices. This work studies the current-controlled, two-step insulator-metal phase transition of VO₂ in varying microwire geometries. Geometry-dependent scaling trends extracted from current-voltage measurements show that the first step induced by carrier injection is delocalized over the microwire, while the second, thermally-induced step is localized to a filament about 1 to 2 μm wide for 100 nm-thick sputtered VO₂ films on SiO₂. These effects are confirmed by direct infrared imaging, which also measures the change in optical absorption in the two steps. The difference between the threshold currents of the two steps increases as the microwires are narrowed. Micron- and sub-micron-wide VO₂ structures can be used to separate the two phase transition steps in photonic and electronic devices. Full article

(This article belongs to the Special Issue Hybrid and Heterogeneous Technologies in Photonics Integrated Circuits)

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314 KiB

Open AccessArticle

Four-Wave Mixing of a Laser and Its Frequency-Doubled Version in a Multimode Optical Fiber

by Hamed Pourbeyram and Arash Mafi

Photonics 2015, 2(3), 906-915; https://doi.org/10.3390/photonics2030906 - 27 Aug 2015

Cited by 12 | Viewed by 5482

Abstract

It is shown that it is possible to couple a laser beam and its frequency-doubled daughter into a multimode optical fiber through the four-wave mixing nonlinear process and generate a new wavelength. The frequency-doubled daughter can be generated in an external crystal with [...] Read more.

It is shown that it is possible to couple a laser beam and its frequency-doubled daughter into a multimode optical fiber through the four-wave mixing nonlinear process and generate a new wavelength. The frequency-doubled daughter can be generated in an external crystal with a large second order nonlinearity. It is argued that while this possibility is within the design parameter range of conventional multimode optical fibers, it necessitates a lower-bound for the core-cladding refractive index contrast of the multimode optical fiber. Full article

(This article belongs to the Special Issue Nonlinear Fiber Optics)

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2739 KiB

Open AccessArticle

Photonic Nanostructures Design and Optimization for Solar Cell Application

by Qian Liu, Eric Sandgren, Miles Barnhart, Rui Zhu and Guoliang Huang

Photonics 2015, 2(3), 893-905; https://doi.org/10.3390/photonics2030893 - 26 Aug 2015

Cited by 6 | Viewed by 5545

Abstract

In this paper, a semiconducting photonic nanostructure capable of wide range absorption and tunable optical resonance has been designed with a proposed theoretical optimization model. The design consists of ZnO/CdS core-shell nanowire arrays as well as multilayer thin films that act to absorb [...] Read more.

In this paper, a semiconducting photonic nanostructure capable of wide range absorption and tunable optical resonance has been designed with a proposed theoretical optimization model. The design consists of ZnO/CdS core-shell nanowire arrays as well as multilayer thin films that act to absorb incident electromagnetic (EM) waves over a broad frequency range. Theoretical, as well as numerical, studies of the nanostructure inside a solar cell plate have been conducted in order to validate the proposed microstructural design. Excellent energy absorption rates of EM waves have been achieved in the high frequency range by using the optical resonance of the nanowire array. By combining multilayer thin film with the core-shell nanowire in the unit cell of a photonic solar cell, a broadband high absorption has been achieved. Moreover, the geometry of the proposed photonic nanostructure is obtained through the implementation of a genetic algorithm. This avoids local minima and an optimized absorption rate of ~90% over the frequency range of 300 to 750 THz has been obtained in the solar cell. Full article

(This article belongs to the Special Issue New Frontiers in Plasmonics and Metamaterials)

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1648 KiB

Open AccessArticle

Multipoles of Even/Odd Split-Ring Resonators

by Andrew Chen, Ashok Kodigala, Thomas Lepetit and Boubacar Kanté

Photonics 2015, 2(3), 883-892; https://doi.org/10.3390/photonics2030883 - 5 Aug 2015

Cited by 6 | Viewed by 6642

Abstract

The ultimate goal of metamaterial engineering is to have complete control over the electromagnetic constitutive parameters in three-dimensional space. This engineering can be done by considering either single meta-atoms or full meta-arrays. We follow the first route and perform numerical simulations of split-ring [...] Read more.

The ultimate goal of metamaterial engineering is to have complete control over the electromagnetic constitutive parameters in three-dimensional space. This engineering can be done by considering either single meta-atoms or full meta-arrays. We follow the first route and perform numerical simulations of split-ring resonators, with different gap numbers and under varying illumination scenarios, to investigate their individual multipolar scattering response. For the fundamental resonance, we observe that odd-gap rings always exhibit overlapping electric and magnetic dipole responses while even-gap rings only exhibit that behavior accidentally. We expect our results to foster progress in the engineering of three-dimensional disordered metamaterials. Full article

(This article belongs to the Special Issue New Frontiers in Plasmonics and Metamaterials)

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1166 KiB

Open AccessArticle

Dynamics of a Low-Dimensional Model for Short Pulse Mode Locking

by Edward D. Farnum and J. Nathan Kutz

Photonics 2015, 2(3), 865-882; https://doi.org/10.3390/photonics2030865 - 3 Aug 2015

Cited by 10 | Viewed by 4193

Abstract

Emerging ultra-fast mode-locked lasers are now capable of generating pulses in the few to sub-femtosecond regime. Using recent theoretical innovations around the short pulse equation, we characterize the mode locking dynamics using a low-dimensional representation of the pulse parameters. The theory is formulated [...] Read more.

Emerging ultra-fast mode-locked lasers are now capable of generating pulses in the few to sub-femtosecond regime. Using recent theoretical innovations around the short pulse equation, we characterize the mode locking dynamics using a low-dimensional representation of the pulse parameters. The theory is formulated using a variational approach, since linearization of the exact solution is not tractable. The dominant dynamics can be characterized in a geometrical way using phase-plane analysis. Of note is our ability to determine the underlying bifurcations that occur due to changes in the fiber laser cavity parameters, including the onset of the multi-pulsing instability. The theory can aid in design principles for generating robust and highly-stable mode-locked pulses. Full article

(This article belongs to the Special Issue Nonlinear Fiber Optics)

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523 KiB

Open AccessArticle

Quantum Dot/Liquid Crystal Nanocomposites in Photonic Devices

by Andrea L. Rodarte, Fredy Cisneros, Jason E. Hein, Sayantani Ghosh and Linda S. Hirst

Photonics 2015, 2(3), 855-864; https://doi.org/10.3390/photonics2030855 - 27 Jul 2015

Cited by 26 | Viewed by 8636

Abstract

Quantum dot/liquid crystal nano-composites are promising new materials for a variety of applications in energy harvesting, displays and photonics including the liquid crystal laser. To realize many applications, however, we need to control and stabilize nano-particle dispersion in different liquid crystal host phases [...] Read more.

Quantum dot/liquid crystal nano-composites are promising new materials for a variety of applications in energy harvesting, displays and photonics including the liquid crystal laser. To realize many applications, however, we need to control and stabilize nano-particle dispersion in different liquid crystal host phases and understand how the particles behave in an anisotropic fluid. An ideal system will allow for the controlled assembly of either well-defined nano-particle clusters or a uniform particle distribution. In this paper, we investigate mesogen-functionalized quantum dots for dispersion in cholesteric liquid crystal. These nanoparticles are known to assemble into dense stable packings in the nematic phase, and such structures, when localized in the liquid crystal defects, can potentially enhance the coupling between particles and a cholesteric cavity. Controlling the dispersion and assembly of quantum dots using mesogenic surface ligands, we demonstrate how resonant fluid photonic cavities can result from the co-assembly of luminescent nanoparticles in the presence of cholesteric liquid crystalline ordering. Full article

(This article belongs to the Special Issue Quantum Dot Based Lasers and Photonic Devices)

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13552 KiB

Open AccessArticle

Effects of Irregular Bimetallic Nanostructures on the Optical Properties of Photosystem I from Thermosynechococcus elongatus

by Imran Ashraf, Sepideh Skandary, Mohammad Y. Khaywah, Michael Metzger, Alfred J. Meixner, Pierre M. Adam and Marc Brecht

Photonics 2015, 2(3), 838-854; https://doi.org/10.3390/photonics2030838 - 23 Jul 2015

Cited by 9 | Viewed by 6405

Abstract

The fluorescence of photosystem I (PSI) trimers in proximity to bimetallic plasmonic nanostructures have been explored by single-molecule spectroscopy (SMS) at cryogenic temperature (1.6 K). PSI serves as a model for biological multichromophore-coupled systems with high potential for biotechnological applications. Plasmonic nanostructures are [...] Read more.

The fluorescence of photosystem I (PSI) trimers in proximity to bimetallic plasmonic nanostructures have been explored by single-molecule spectroscopy (SMS) at cryogenic temperature (1.6 K). PSI serves as a model for biological multichromophore-coupled systems with high potential for biotechnological applications. Plasmonic nanostructures are fabricated by thermal annealing of thin metallic films. The fluorescence of PSI has been intensified due to the coupling with plasmonic nanostructures. Enhancement factors up to 22.9 and 5.1 are observed for individual PSI complexes coupled to Au/Au and Ag/Au samples, respectively. Additionally, a wavelength dependence of fluorescence enhancement is observed, which can be explained by the multichromophoric composition of PSI. Full article

(This article belongs to the Special Issue New Frontiers in Plasmonics and Metamaterials)

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448 KiB

Open AccessArticle

Graphene Plasmonic Waveguides for Mid-Infrared Supercontinuum Generation on a Chip

by Andrey V. Gorbach

Photonics 2015, 2(3), 825-837; https://doi.org/10.3390/photonics2030825 - 23 Jul 2015

Cited by 20 | Viewed by 6785

Abstract

Using perturbation expansion of Maxwell equations with the nonlinear boundary condition, a generic propagation equation is derived to describe nonlinear effects, including spectral broadening of pulses, in graphene surface plasmon (GSP) waveguides. A considerable spectral broadening of an initial 100 fs pulse with [...] Read more.

Using perturbation expansion of Maxwell equations with the nonlinear boundary condition, a generic propagation equation is derived to describe nonlinear effects, including spectral broadening of pulses, in graphene surface plasmon (GSP) waveguides. A considerable spectral broadening of an initial 100 fs pulse with 0.5 mW peak power in a 25 nm wide and 150 nm long waveguide is demonstrated. The generated supercontinuum covers the spectral range from 6 μm to 13 μm . Full article

(This article belongs to the Special Issue New Frontiers in Plasmonics and Metamaterials)

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1188 KiB

Open AccessArticle

Dynamics of a Dispersion-Managed Passively Mode-Locked Er-Doped Fiber Laser Using Single Wall Carbon Nanotubes

by Norihiko Nishizawa, Lei Jin, Hiromichi Kataura and Youichi Sakakibara

Photonics 2015, 2(3), 808-824; https://doi.org/10.3390/photonics2030808 - 21 Jul 2015

Cited by 18 | Viewed by 7243

Abstract

We investigated the dynamics of a dispersion-managed, passively mode-locked, ultrashort-pulse, Er-doped fiber laser using a single-wall carbon nanotube (SWNT) device. A numerical model was constructed for analysis of the SWNT fiber laser. The initial process of passive mode-locking, the characteristics of the output [...] Read more.

We investigated the dynamics of a dispersion-managed, passively mode-locked, ultrashort-pulse, Er-doped fiber laser using a single-wall carbon nanotube (SWNT) device. A numerical model was constructed for analysis of the SWNT fiber laser. The initial process of passive mode-locking, the characteristics of the output pulse, and the dynamics inside the cavity were investigated numerically for soliton, dissipative-soliton, and stretched-pulse mode-locking conditions. The dependencies on the total dispersion and recovery time of the SWNTs were also examined. Numerical results showed similar behavior to experimental results. Full article

(This article belongs to the Special Issue Nonlinear Fiber Optics)

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468 KiB

Open AccessArticle

Optical Nanofiber Integrated into Optical Tweezers for In Situ Fiber Probing and Optical Binding Studies

by Ivan Gusachenko, Viet Giang Truong, Mary C. Frawley and Síle Nic Chormaic

Photonics 2015, 2(3), 795-807; https://doi.org/10.3390/photonics2030795 - 2 Jul 2015

Cited by 11 | Viewed by 7435

Abstract

Precise control of particle positioning is desirable in many optical propulsion and sorting applications. Here, we develop an integrated platform for particle manipulation consisting of a combined optical nanofiber and optical tweezers system. We show that consistent and reversible transmission modulations arise when [...] Read more.

Precise control of particle positioning is desirable in many optical propulsion and sorting applications. Here, we develop an integrated platform for particle manipulation consisting of a combined optical nanofiber and optical tweezers system. We show that consistent and reversible transmission modulations arise when individual silica microspheres are introduced to the nanofiber surface using the optical tweezers. The observed transmission changes depend on both particle and fiber diameter and can be used as a reference point for in situ nanofiber or particle size measurement. Thence, we combine scanning electron microscope (SEM) size measurements with nanofiber transmission data to provide calibration for particle-based fiber assessment. This integrated optical platform provides a method for selective evanescent field manipulation of micron-sized particles and facilitates studies of optical binding and light-particle interaction dynamics. Full article

(This article belongs to the Special Issue Optical Trapping in Biology and Nanotechnology)

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5827 KiB

Open AccessArticle

Eccentrically-Layered Active Coated Nano-Particles for Directive Near- and Far-Field Radiation

by Rasmus Ø. Thorsen and Samel Arslanagić

Photonics 2015, 2(3), 773-794; https://doi.org/10.3390/photonics2030773 - 29 Jun 2015

Cited by 8 | Viewed by 5417

Abstract

The present work shows how the eccentricity in active nano-particles may lead to very interesting and rather directive near- and far-field radiation patterns. The nano-particle is of a three-layer type and consists of a silica core, a free-space middle layer and an outer [...] Read more.

The present work shows how the eccentricity in active nano-particles may lead to very interesting and rather directive near- and far-field radiation patterns. The nano-particle is of a three-layer type and consists of a silica core, a free-space middle layer and an outer silver shell and is excited by a magnetic line source. The constant frequency gain model is included in the silica core, and the eccentricity is introduced through appropriate displacements of the core. It is shown that the eccentricity in a nano-particle, which was initially designed to excite a strong dipole mode, causes a progressively larger excitation of several other (including higher order) modes, this being more so the larger the core displacement. Specifically, eccentric nano-particles are identified with comparable simultaneous excitations of dipole and quadrupole modes, with associated large values of the radiated power and, even more notably, enhanced and directive near- and far-field radiation patterns. The main beam of these patterns is shown to be effectively tailored (enhanced, reshaped and steered) by the direction and amount of the core displacement. The eccentric nano-particles can be additionally gain optimized to boost their near-field response and the radiated power, while retaining the directivity of the gain unoptimized eccentric cases. Owing to their very directive nearand far-field patterns, the proposed eccentric, active three-layer nano-particles may provide alternative strategies towards the design of directive nano-antennas relative to several of the existing solutions. Full article

(This article belongs to the Special Issue New Frontiers in Plasmonics and Metamaterials)

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1631 KiB

Open AccessArticle

Developing a New Biophysical Tool to Combine Magneto-Optical Tweezers with Super-Resolution Fluorescence Microscopy

by Zhaokun Zhou, Helen Miller, Adam J.M. Wollman and Mark C. Leake

Photonics 2015, 2(3), 758-772; https://doi.org/10.3390/photonics2030758 - 26 Jun 2015

Cited by 15 | Viewed by 10702

Abstract

We present a novel experimental setup in which magnetic and optical tweezers are combined for torque and force transduction onto single filamentous molecules in a transverse configuration to allow simultaneous mechanical measurement and manipulation. Previously we have developed a super-resolution imaging module which, [...] Read more.

We present a novel experimental setup in which magnetic and optical tweezers are combined for torque and force transduction onto single filamentous molecules in a transverse configuration to allow simultaneous mechanical measurement and manipulation. Previously we have developed a super-resolution imaging module which, in conjunction with advanced imaging techniques such as Blinking assisted Localisation Microscopy (BaLM), achieves localisation precision of single fluorescent dye molecules bound to DNA of ~30 nm along the contour of the molecule; our work here describes developments in producing a system which combines tweezing and super-resolution fluorescence imaging. The instrument also features an acousto-optic deflector that temporally divides the laser beam to form multiple traps for high throughput statistics collection. Our motivation for developing the new tool is to enable direct observation of detailed molecular topological transformation and protein binding event localisation in a stretching/twisting mechanical assay that previously could hitherto only be deduced indirectly from the end-to-end length variation of DNA. Our approach is simple and robust enough for reproduction in the lab without the requirement of precise hardware engineering, yet is capable of unveiling the elastic and dynamic properties of filamentous molecules that have been hidden using traditional tools. Full article

(This article belongs to the Special Issue Optical Trapping in Biology and Nanotechnology)

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Photonics, Volume 2, Issue 3 (September 2015) – 17 articles , Pages 758-1026

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