Colloidal nanophotonics: the emerging technology platform

Abstract

Dating back to decades or even centuries ago, colloidal nanophotonics during the last ten years rapidly extends towards light emitting devices, lasers, sensors and photonic circuitry to manifest itself as an emerging technology platform rather than an entirely academic research field.

Strongly Optical Absorbing Nanostructures Containing Metal Quantum Dots: Theory

“…The estimates of oscillator strength of the transition f 2,1;1,0 (S) (8), dipole moment of the transition D 2,1;1,0 (S) (6), polarizability A''(ω, a) (11), and cross section σ abs (ω,a) (9) of absorption of a light wave with frequency ω (in this case, ratio (ω/ω 2,1 (S)) 2 =9 10 -2 and the wave frequency ω lies in the infrared region) at the above Coulomb states of the electron appearing over a spherical surface (QD of metal -matrix silicate glass) are given in the table. If we take into account the fact (see the table) that the oscillator strength f 2,1;1,0 ≈ 0.4 and the dipole moment D 2,1;1,0 ≈ 1.85 (where ( e D = 0 Ǻ), (Debye)) of the transition over a spherical surface QDs of metal of radii a=10 nm assume giant values (exceeding the typical values of oscillator strength and dipole moments in matrix silicate glass by two orders of magnitude [1][2][3][4][5] and dipole transitions between the nearest Coulomb levels E nl (a) (4) in QDs in the electromagnetic field are allowed by the selection rules with a change (or preservation) of principal quantum number n and with a change in orbital quantum number l by unity [7], the quasi-zero-dimensional nanosystems under investigation are obviously strongly absorbing nanostructures for infrared radiation.…”

“…At present, the optical and electro optical [1][2][3][4][5][6] properties of quasizero-dimensional structures are extensively studied. Such structures commonly consist of spherical semiconductor, metal and insulator nanocrystals (the so-called quantum dots (QDs)) with a radius a ≈ 1-10 2 grown in dielectric (or semiconductor) matrices.…”

“…Such structures commonly consist of spherical semiconductor, metal and insulator nanocrystals (the so-called quantum dots (QDs)) with a radius a ≈ 1-10 2 grown in dielectric (or semiconductor) matrices. The studies in this field are motivated by the fact that such nanoheterosystems represent new promising materials for the development of new elements of nanooptoelectronics to be used, specifically, for controlling optical signals in optical computers or for manufacturing active layers of optical lasers [1] as well as new strongly absorbing nanomaterials [7]. Special attention is paid to analysis of optical properties of such nanosystems in view of its unique photoluminescence properties and the ability to effectively emit light in the visible or near infrared ranges at room temperatures [1].…”

Colloidal Photoluminescent Refractive Index Nanosensor Using Plasmonic Effects

“…Spheroids are supposed to represent a reasonable approximation for nanorods [17]. Both types of particles can be obtained by means of colloidal chemistry without lithography, epitaxy and etching thus enabling chip and versatile bottom-up engineering meeting the general concept of colloidal photonics as an emerging technology platform [18]. The most favorable situations for fluorescence enhancement are shown in Figure 1.…”

Sideband pump-probe technique resolves nonlinear modulation response of PbS/CdS quantum dots on a silicon nitride waveguide

“…[1][2][3][4] This tunability, their long coherence lifetime, 5,6 and the relatively low cost and scalability of the wet-chemical production, i.e., vacuum-free deposition methods such as spincoating, make colloidal QDs an attractive choice as active medium in photonic applications. 7,8 Based on a variety of different material systems, light emitting devices and lasers have been fabricated using colloidal nanocrystals, recently even on chip. [9][10][11][12][13] As photonic devices mature, energy efficiency is becoming increasingly important.…”