Amplified spontaneous emission in polymer–CdSe/ZnS-nanocrystal DFB structures produced by the holographic method

Abstract

Amplified spontaneous emission (ASE) is demonstrated in volume-distributed feedback (DFB) structures, formed by colloidal CdSe/ZnS nanocrystals and ZrO2 nanoparticles (NPs) in a polymer matrix. Periodic redistribution of the NPs in an organic matrix was carried out by holographic photopolymerization in a specially developed light-sensitive nanocomposite. The composite consists of two acrylate monomers and two types of inorganic NPs. The NPs provide for the formation of two co-phased gratings-a refractive index grating and an optical gain (losses) grating. The core-shell CdSe/ZnS nanocrystals are used as a gain medium, while ZrO2 NPs create the refractive index grating and enhance the distributed feedback. The period of the volume structure provides the feedback for lasing at the wavelength lambda(las) of about 575 nm in the second diffraction order. In contrast to known laser systems based on volume DFB cavities, in which the different components of the formulation provide optical gain and feedback, in our case the inorganic NPs serve as an emitting material and can provide simultaneously for feedback. By pumping of DFB structures by a titanium-sapphire laser (lambda(pump) = 400 nm, pulse duration of 120 fs) normal to the sample plane, the appearance of a sharp stimulated emission along the grating-vector direction is observed. Output intensity of ASE as a function of the pump energy shows a threshold behavior and full width at half-maximum (FWHM) of the ASE spectral band decreases from 33 to 12 nm.

Active photonic devices based on colloidal semiconductor nanocrystals and organometallic halide perovskites

“…Therefore, a polymer nanocomposite containing semiconductor nanocrystals results a flexible material which joins the active properties of the nanoparticles together with the technological feasibilities of the polymer matrices [4,76]. For example, a DFB grating fabricated on polymers containing CdSe/ZnS QDs have been proposed to demonstrate lasing [80,81], even under nanosecond excitation [81].…”

Photocurable Polymer Nanocomposites for Magnetic, Optical, and Biological Applications

“…Nanoparticles with a photothermal effect, such as gold nanoparticles (AuNPs) and CNT, are used for NIR-driven drug release. (Reproduced from [54], [69]- [71], [87], [98], [112], and [121].) for biomedical usage, by successfully implanting them into rabbit eyes without significant biological damage, as shown in Fig.…”

“…Smirnova and coworkers encapsulated CdSe/ZnS nanocrystals and ZrO2 NPs and prepared distributed feedback (DFB) structures by holographic lithography [112]. In doing so, they achieved amplified spontaneous emission, and proved that a DFB structure composed of QDs confined in polymer matrix displays enhanced light emission intensity and a narrower peak width (shown in Fig.…”

Diffractive-Optical Elements via All-Optical Patterning of Photopolymers and Nanocomposites

“…The lightemissive high RI NP can provide optical feedback and serve as a gain medium at the same time. We have shown that the DFB-cavities based on polymer grating doped emissive CdSe/ZnS quantum dots as a gain medium and containing ZrO 2 NP to enhance the feedback efficiency perform a sharp amplified spontaneous emission (ASE) by pumping with fs Ti-sapphire laser pulses [26].…”