The aim of this work was to improve the laser performance, in terms of threshold and operational lifetime, of lasers based on polymer films doped with perylenediimide (PDI) derivatives as active media. For such purpose, we first investigated the amplified spontaneous emission (ASE) properties of perylene orange (PDI-O), when doped into polystyrene (PS) films. Lower ASE thresholds and larger photostabilities than those of similar films containing another PDI derivative (PDI-C6), recently reported in the literature, have been measured. Results have been interpreted in terms of the photoluminescence efficiency of the films, which depends on the type of molecular arrangement, inferred with the help of nuclear magnetic resonance experiments. We also show that PS films have a better ASE performance, i.e. lower thresholds and larger photostabilities, than those based on poly(methyl methacrylate), which was recently highlighted as one of the best matrixes for PDI-O. Finally, a one-dimensional second-order distributed feedback laser using PS doped with PDI-O was fabricated and characterized. This device has shown a threshold significantly lower (by around one order of magnitude) than that of a similar laser based on PDI-C6-doped PS.

We report on the fabrication of efficient organic distributed feedback (DFB) lasers with thermally-nanoimprinted active films, emitting between 565 and 580 nm. The use of thermal-NIL has allowed, as opposed to room temperature or solvent-assisted techniques, high grating quality and excellent modulation depth. The 155°C heat exposure of the NIL process, does not significantly affect the thermal and optical properties of the active material (polystyrene films doped with a perylenediimide derivative). These devices combine a simple and low-cost preparation method with good laser characteristics, i.e. thresholds of 1 μJ/pulse, single-mode emission with linewidths below 0.2 nm and photostability half-lives of ~ 10⁵ pump pulses under ambient conditions. In comparison to more standard DFBs with gratings on the substrate, their fabrication is much easier, while they show a similar laser performance.

The effect of varying film thickness ($h$) on the amplified spontaneous emission (ASE) properties of $0.5\mathrm{wt}\mathrm{.}\%$ perylenediimide-doped polystyrene waveguides is reported. The threshold dependence on $h$, not previously investigated in detail, is analyzed in terms of the film absorption and photoluminescence, the confinement of the fundamental waveguide mode (${\mathrm{TE}}_0$), and the presence of high-order modes. For $h<400\mathrm{nm}$ and down to 150 nm, the ASE wavelength blueshifts, while the linewidth and threshold increase. The detrimental ASE operation in very thin films is due to the low absorption as well as to the poor confinement of the ${\mathrm{TE}}_0$ mode.

The design, synthesis and evaluation of the amplified spontaneous emission (ASE) properties of a series of arylalkynyl-benzo[c][1,2,5]thiadiazole (BTD) and [1,2,5]thiadiazolo[3,4-g]quinoxaline (TDQ) derivatives are described. The synthetic strategy entailed the use of Sonogashira and Stille reactions based on the different aromatic natures of the two cores. The ASE properties were measured in thin polystyrene (PS) films doped with different concentrations of the synthesised compounds. BTD derivatives showed narrowing of the photoluminescence spectra (PL), thus revealing their potential laser applications. Only one TDQ derivative showed ASE. X-ray diffraction analysis was carried out to understand the observed results and to establish structure–property relationships. Molecules that showed strong molecular packing quenched the PL emission, thus giving rise to higher ASE thresholds. This is the first study in which ASE has been studied in BTD and TDQ derivatives and it represents a step forward in understanding this class of compounds for laser applications.

In this paper, we theoretically and experimentally evaluated the quality of volume phase transmission lenses stored in an environmentally friendly photopolymer. Holographic lenses (HLs) were obtained using symmetrical and asymmetrical experimental setups with the same positive and negative focal length and pupil diameter. The image quality was evaluated from the calculation of the modulation transfer function (MTF) by capturing the point spread function (PSF) with a charge-coupled device (CCD). A maximum frequency of 14 L/mm, reaching an MTF value of 0.1, was obtained for a negative asymmetrically recorded HL, evaluated at 473 nm wavelength. A theoretical study of aberrations was carried out to qualitatively evaluate the experimental results obtained.