Graphene Oxide-Based Silico-Phosphate Composite Films for Optical Limiting of Ultrashort Near-Infrared Laser Pulses

Abstract

The development of graphene-based materials for optical limiting functionality is an active field of research. Optical limiting for femtosecond laser pulses in the infrared-B (IR-B) (1.4–3 μm) spectral domain has been investigated to a lesser extent than that for nanosecond, picosecond and femtosecond laser pulses at wavelengths up to 1.1 μm. Novel nonlinear optical materials, glassy graphene oxide (GO)-based silico-phosphate composites, were prepared, for the first time to our knowledge, by a convenient and low cost sol-gel method, as described in the paper, using tetraethyl orthosilicate (TEOS), H3PO4 and GO/reduced GO (rGO) as precursors. The characterisation of the GO/rGO silico-phosphate composite films was performed by spectroscopy (Fourier-transform infrared (FTIR), Ultraviolet–Visible-Near Infrared (UV-VIS-NIR) and Raman) and microscopy (atomic force microscopy (AFM) and scanning electron microscope (SEM)) techniques. H3PO4 was found to reduce the rGO dispersed in the precursor’s solution with the formation of vertically agglomerated rGO sheets, uniformly distributed on the substrate surface. The capability of these novel graphene oxide-based materials for the optical limiting of femtosecond laser pulses at 1550 nm wavelength was demonstrated by intensity-scan experiments. The GO or rGO presence in the film, their concentrations, the composite films glassy matrix, and the film substrate influence the optical limiting performance of these novel materials and are discussed accordingly.

Effect of P2O5 Content on Luminescence of Reduced Graphene-Oxide-Doped ZnO–P2O5 Nano-Structured Films Prepared via the Sol–Gel Method

“…The vibration modes of the silica-based glass substrate with broad bands centered at around 760 and 910 cm −1 and assigned to the Si-O- (stretching mode) in the range 750–760 cm −1 and 890–975 cm −1 were present in all the samples. The information from the 1 mm thickness of the glass substrate overlapped with the information received from the films with a thickness of only hundreds of nanometers [ 28 ]. However, in some samples, new shoulders were noticed, and after deconvolution, these new bands, identified in all samples, containing rGO and P 2 O 5 at 988–1010 cm −1 , were ascribed to the overlapping of the Si-O vibrational modes with C-O-C stretching (epoxy group) [ 29 ] and with υs Si-O-P in samples containing phosphorous [ 30 , 31 ].…”

An Overview of Functionalized Graphene Nanomaterials for Advanced Applications

“…GO was incorporated into a silico-phosphate glassy matrix via the sol-gel method to construct films capable of exerting optical limiting functions for femtosecond laser pulses in the infrared-B spectral region [ 61 ]. Additionally, fluorographene can be conveniently used in OL applications, and in this regard, Stathis et al [ 62 ] proposed a series of N -octylamine-modified fluorographenes with tunable NLO response.…”

Enhancement of Broadband Reverse Saturable Absorption of Red/Black Phosphorus Heterojunction

“…As carriers, the NLO materials play an important role in achieving OL functionality [ 11 ]. There is a wide range of materials that can be used for optical limiting, such as organic polymers [ 12 ], inorganic metal compounds [ 13 ], and composites [ 14 ]. For several years, researchers have been attempting to explore new NLO materials with larger modulation depths, lower initial limiting thresholds, faster response times, and wider response wavebands.…”