Quantum trajectory analysis of single-photon control from a single-molecule source

Over the years, fluorescence microscopy has evolved and has become a necessary element of life science studies. Microscopy has elucidated biological processes in live cells and organisms, and also enabled tracking of biomolecules in real time. Development of highly sensitive photodetectors and light sources, in addition to the evolution of various illumination methods and fluorophores, has helped microscopy acquire single-molecule fluorescence sensitivity, enabling single-molecule fluorescence imaging and detection. Low-light photodetectors used in microscopy are classified into two categories: point photodetectors and wide-field photodetectors. Although point photodetectors, notably photomultiplier tubes (PMTs), have been commonly used in laser scanning microscopy (LSM) with a confocal illumination setup, wide-field photodetectors, such as electron-multiplying charge-coupled devices (EMCCDs) and scientific complementary metal-oxide-semiconductor (sCMOS) cameras have been used in fluorescence imaging. This review focuses on the former low-light point photodetectors and presents their fluorescence microscopy applications and recent progress. These photodetectors include conventional PMTs, single photon avalanche diodes (SPADs), hybrid photodetectors (HPDs), in addition to newly emerging photodetectors, such as silicon photomultipliers (SiPMs) (also known as multi-pixel photon counters (MPPCs)) and superconducting nanowire single photon detectors (SSPDs). In particular, this review shows distinctive features of HPD and application of HPD to wide-field single-molecule fluorescence detection.

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ORGANIC SEMICONDUCTOR MICRO-PILLAR PROCESSED BY FOCUSED ION BEAM MILLING

International Journal of Quantum Information ◽

10.1142/s0219749905001407 ◽

2005 ◽

Vol 03 (supp01) ◽

pp. 223-228 ◽

Cited By ~ 1

Author(s):

WEN-CHANG HUNG ◽

A. ADAWI ◽

A. TAHRAOUI ◽

A. G. CULLIS

Keyword(s):

Quantum Dot ◽

Single Molecule ◽

Focused Ion Beam ◽

Single Photon ◽

Ion Beam ◽

Photon Emission ◽

Micro Machining ◽

Single Photon Emission ◽

Fabrication Procedure ◽

Pillar Structure

In order to control light, different strategies have been applied by placing an optically active medium into a semiconductor resonator and certain applications such as LEDs and laser diodes have been commercialized for many years. The possibility of nanoscale optical applications has created great interesting for quantum nanostructure research. Recently, single photon emission has been an active area of quantum dot research. A quantum dot is place between distributed Bragg reflectors (DBRs) within a micro-pillar structure. In this study, we shall report on an active layer composed of an organic material instead of a semiconductor. The micro-pillar structure is fabricated by a focused ion beam (FIB) micro-machining technique. The ultimate target is to achieve a single molecule within the micro-pillar and therefore to enable single photon emission. Here, we demonstrate some results of the fabrication procedure of a 5 micron organic micro-pillar via the focused ion beam and some measurement results from this study. The JEOL 6500 dual column system equipped with both electron and ion beams enables us to observe the fabrication procedure during the milling process. Furthermore, the strategy of the FIB micro-machining method is reported as well.

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Development of new photon-counting detectors for single-molecule fluorescence microscopy

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0035 ◽

2013 ◽

Vol 368 (1611) ◽

pp. 20120035 ◽

Cited By ~ 79

Author(s):

X. Michalet ◽

R. A. Colyer ◽

G. Scalia ◽

A. Ingargiola ◽

R. Lin ◽

...

Keyword(s):

Fluorescence Microscopy ◽

Single Molecule ◽

Single Photon ◽

Photon Counting ◽

Wide Field ◽

Fluorescence Lifetime Imaging ◽

Large Area ◽

Single Molecule Fluorescence ◽

Single Photon Counting ◽

Single Molecule Fluorescence Microscopy

Two optical configurations are commonly used in single-molecule fluorescence microscopy: point-like excitation and detection to study freely diffusing molecules, and wide field illumination and detection to study surface immobilized or slowly diffusing molecules. Both approaches have common features, but also differ in significant aspects. In particular, they use different detectors, which share some requirements but also have major technical differences. Currently, two types of detectors best fulfil the needs of each approach: single-photon-counting avalanche diodes (SPADs) for point-like detection, and electron-multiplying charge-coupled devices (EMCCDs) for wide field detection. However, there is room for improvements in both cases. The first configuration suffers from low throughput owing to the analysis of data from a single location. The second, on the other hand, is limited to relatively low frame rates and loses the benefit of single-photon-counting approaches. During the past few years, new developments in point-like and wide field detectors have started addressing some of these issues. Here, we describe our recent progresses towards increasing the throughput of single-molecule fluorescence spectroscopy in solution using parallel arrays of SPADs. We also discuss our development of large area photon-counting cameras achieving subnanosecond resolution for fluorescence lifetime imaging applications at the single-molecule level.

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