Quantum lithography

Abstract Optical techniques for three-dimensional micro- and nanostructuring of transparent and photo-sensitive materials are reviewed with emphasis on methods of manipulation of the optical field, such as beam focusing, the use of ultrashort pulses, and plasmonic and near-field effects. The linear and nonlinear optical response of materials to classical optical fields as well as exploitation of the advantages of quantum lithography are discussed. 

Keywords Laser lithography Optical nonlinearities Optical structm-ing Photopolymerization Quantum lithography... 

Fig. 15 Schematic implementation of quantum lithography with photon pairs generated in SPDC. Two-photon absorbing photoresist is used as a recording medium. SPDC signal and idler photons are overlapped on a beamsplitter, and exit either of its output ports together. Exposure patterns due to classical and quantum interference are shown in the long and short amplitudes, respectively...

The expressions given in the preceding section can be used for the estimation of the TPA rates, and help gain the insight into the approximate conditions needed for practical quantum lithography. A direct demonstration of record-... 

In the traditional lithography approach, researchers continued to consider the idea that modem STM (scanning tunnel Microscopy) could be the proper tool for the formation of two-junction systems when working with very small particles. This consideration had related the studies of single-electron phenomena to the concept of quantum dots (Glazman and Shechter 1989). 

In the 1980s, CdSe quantum dots vere prepared by top-dovm techniques such as lithography ho vever, size variations, crystal defects, poor reproducibility, and poor optical properties of quantum dots made them inadequate for advanced applications. Introduction of bottom-up colloidal synthesis of CdSe quantum dots by Murray et al. [3] and its further advancements brought radical changes in the properties of quantum dots and their applications in devices and biology. The colloidal syntheses of CdSe quantum dots are broadly classified into organic-phase synthesis and aqueous-phase synthesis. 

In order to investigate this effect, ordered arrays of metallic nano-islands were fabricated on glass substrates by a process of natural lithography using monodisperse polystyrene nanospheres. The metal particle dimensions were tailored in order to tune the plasmon resonance wavelength to match the spectral absorption of the fluorophore. The fluorophore, Cy5 dye, which is widely used in optical immunoassays and has a medium quantum efficiency ( 0.3), was used in this preliminary study of the plasmonic enhancement effect. 

Fig. 12.7 InGaAsP/InP multi quantum well semiconductor structure process (a) Si02 etch mask deposition (b) PMMA spin coating (c) E beam lithography and develop (d) Si02 etch (e) PMMA stripping (f) InGaAsP membrane etch (g) Si02 stripping (h) Chip flipping and bonding to sapphire (i) InP substrate etch (j) Adhesive etch...

Quantum dots are the engineered counterparts to inorganic materials such as groups IV, III-V and II-VI semiconductors. These structures are prepared by complex techniques such as molecular beam epitaxy (MBE), lithography or self-assembly, much more complex than the conventional chemical synthesis. Quantum dots are usually termed artificial atoms (OD) with dimensions larger than 20-30 nm, limited by the preparation techniques. Quantum confinement, single electron transport. Coulomb blockade and related quantum effects are revealed with these OD structures (Smith, 1996). 2D arrays of such OD artificial atoms can be achieved leading to artificial periodic structures. 

Boto A, Kok P, Abrams D, Braunstein S, Williams C, Dowling J (2000) Quantum interferometric optical lithography exploiting entanglement to beat the diffraction limit. Phys Rev Lett 85 2733-2736... 

Boyd R, Bentley S (2006) Recent progress in quantum and nonlinear optical lithography. Mod) Opt 53 713-718... 

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