The effects of metallic contacts on the lasing characteristics of organic thin films
doi:10.37188/CO.2020-0007
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摘要:金属触点引起的光学损耗被认为是阻碍电泵浦有机 器发展的主要障碍。本文对于存在金属接触电极的有机薄膜,通过设计适当的分布反馈结构形成多通道发射和表面等离子体激元(SPs),从而实现光泵浦 。与采用无金属接触电极的有机薄膜进行对比,结果表明,本文方法可实现更好的 性能。利用本文设计的结构,在740 nm光栅结构的Ag衬底上实现了(0.026 mJ/pulse)的 发射。由于本文设计方法没有增加器件厚度,所以当光学性能得到改善时,电性能并没有降低。Abstract:Optical loss caused by metallic contacts are thought to be a major obstacle to the achievement of organic laser diodes. We find that multi-channel emissions and Surface Plasmons (SPs) by designing a proper distributed feedback structure can allow successful lasing in organic thin films in the presence of contacting electrodes and even show better lasing performance when compared to metal-free cases. In this paper, a lower threshold (0.026 mJ/pulse) laser emission is achieved with the Ag metal electrode on the grating structure with a period of 740 nm. Since there is no increase in device thickness, the electrical properties are not reduced when the optical properties are improved.
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Key words:
- organic laser/
- surface plasmons/
- grating coupling
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Figure 4.Output emission intensity integrated over all wavelengths as a function of the pump intensity for metal-free device (circles); DCJTI:PVK films with quartz substrate and Al-backed device (stars); DCJTI:PVK films with a grating period of 740 nm. The inset shows the grating coupling processes between the waveguide mode and lasing emission under the fourth Bragg condition
Figure 5.Output emission intensity integrated over all wavelengths as a function of the pump intensity for metal-free device (rectangles); DCJTI:PVK films with quartz substrate, Al-backed device (triangles); DCJTI:PVK films and Ag-backed device (stars); DCJTI:PVK films with a grating period of 740 nm. The inset shows the exiting and coupling processes between the lasing light and the SPs mode
Table 1.ASE characteristics of DCJTI:PVK films with quartz substrate and lasing characteristics of distributed feedback lasers (gain material DCJTI:PVK) with grating period of 400 nm and 740 nm.
Metal layer Period /nm Threshold /(mJ·pulse−1) Wavelength /nm FWHM /nm (none) (flat substrate) 0.057 635 12.4 Al (flat substrate) 0.37 632 11.8 Ag (flat substrate) 0.41 632 12.1 (none) 400 0.03 641 0.13 Al 400 0.13 637 0.15 Ag 400 0.16 640 0.23 (none) 740 0.06 613 0.32 Al 740 0.067 612 0.25 Ag 740 0.026 615 0.37 -
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