Influence of an Interfacial Effect on the Laser Performance of a Rhodamine 6G/Cellulose Acetate Waveguide on a Vinylidene Fluoride Copolymer Layer

Abstract

The fluorescent properties of dyes and fluorophores in condensed matter significantly affect the laser performance of organic dye lasers and fluorescent polymer lasers. Concentration quenching of fluorescence is commonly observed in condensed matter. Several approaches have been presented to suppress such quenching, such as the use of a dendrimer and the use of effective energy transfer in a guest-host system. The enhanced fluorescence of rhodamine 6G (R6G) dye on a vinylidene fluoride polymer is an alternative method for enhancing laser performance because of the roughness of the P(VDF-TrFE) surface and the interaction between polar β-crystals of P(VDF-TrFE) and R6G dye. In this paper, a significant improvement in slope efficiency (SE) is demonstrated without a significant depression in the lasing threshold for distributed feedback (DFB) and distributed Bragg reflector (DBR) lasers fabricated using an R6G-dispersed cellulose acetate (CA) matrix spin-coated onto a copolymer of vinylidene fluoride and trifluoroethylene P(VDF-TrFE) thin film. SEs of 3.4 and 1.3% were measured for DBR and DFB laser devices with CA/R6G on a P(VDF-TrFE) thin film, respectively, whereas an SE of less than 1.0% was measured for both corresponding laser devices without a P(VDF-TrFE) thin film. From the aspect of simple fabrication procedures, repeatability in device fabrication and performance, stability of the device, time for device fabrication, the present approach is the most preferable way for industrial applications, requiring only the additional step of spin-coating of a P(VDF-TrFE) thin film.

High-Performance All-Organic DFB and DBR Waveguide Laser with Various Grating Height Fabricated by a Two-Photon Absorption DLW Method

“…The threshold of 0.039 mJ cm −2 pulse −1 and the slope efficiency of 10.2% were measured for the R6G/CA waveguide laser device. The slope efficiency of 10.2% is higher than the previously reported values of 2.0% 8 , 3.4% 6 , and 8.0% 14 and close to 12% 12 for the same R6G/CA waveguide type DFB laser devices. In this DFB device geometries, the corrugated area (grating underneath) acts as a waveguide DBR mirror for the gain medium of active layer in the uncorrugated area (no grating underneath) located between the waveguide edge and the waveguide DBR mirror.…”

“…In our previous studies 6–11 , DFB structures were fabricated using a negative photoresist and the laser performances of the threshold and the slope efficiency were investigated. For m = 1, the grating pitch is 200 nm and the grating width is 100 nm, and as m is increased, the grating pitch is 200 × m and the grating width is 100 × m .…”

“…Furthermore, the organic photoresist materials can be easily used for the fabrication of the sequence of the microcavity for the DFB and the distributed Bragg reflector (DBR) structures. Interference of two laser beams can be used to fabricate the sequence of the grating structures for DFB laser devices 6–11 . The slope efficiency and the threshold for lasing are the key parameters for the light-pumped DFB lasers.…”

Low-Threshold Microlasers Based on Holographic Dual-Gratings

“…Different types of gain materials have been applied to microcavity lasers, including dyes, polymers, and colloidal quantum dots (CQDs) [1][2][3][4][5][6]. CQDs have demonstrated great potential for use as gain materials because of advantages that include their high photoluminescence quantum yields (PLQYs) and the low-cost and effective chemical manufacturing processes required [7].…”

Self-Aligned Emission of Distributed Feedback Lasers on Optical Fiber Sidewall

“…Compared with other methods, laser interference lithography is a low-cost and facile route to fabricate the grating, which could offer additional degrees of freedom for manipulating the performance of DFB polymer lasers. To date, some gain materials were suitable for DFB lasers, including polymers, dyes, perovskite, and colloidal quantum dots (CQDs) [ 9 , 10 , 11 , 12 , 13 , 14 ]. CQDs exhibit great potential as gain materials due to the excellent photoluminescence quantum yield (PLQY), great Stokes shift, widely tunable bandgaps, and low-cost effective chemical manufacturing [ 15 , 16 , 17 , 18 , 19 ].…”