Saturated evanescent-wave absorption of few-layer graphene-covered side-polished single-mode fiber for all-optical switching

Nanophotonics

article

Kaung-Jay Peng¹  Chun-Lung Wu¹  Yung-Hsiang Lin¹  Hwai-Yung Wang¹  Chih-Hsien Cheng¹  Yu-Chieh Chi¹  Gong-Ru Lin¹ 

[1] Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University (NTU)

关键词: graphene;    all-optical switching;    saturated evanescent-wave absorption;   

DOI  :  10.1515/nanoph-2016-0182

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Using the evanescent-wave saturation effect of hydrogen-free low-temperature synthesized few-layer graphene covered on the cladding region of a side-polished single-mode fiber, a blue pump/infrared probe-based all-optical switch is demonstrated with specific wavelength-dependent probe modulation efficiency. Under the illumination of a blue laser diode at 405 nm, the few-layer graphene exhibits cross-gain modulation at different wavelengths covering the C- and L-bands. At a probe power of 0.5 mW, the L-band switching throughput power variant of 16 μW results in a probe modulation depth of 3.2%. Blue shifting the probe wavelength from 1580 to 1520 nm further enlarges the switching throughput power variant to 24 mW and enhances the probe modulation depth to 5%. Enlarging the probe power from 0.5 to 1 mW further enlarges the switching throughput power variant from 25 to 58 μW to promote its probe modulation depth of up to 5.8% at 1520 nm. In contrast, the probe modulation depth degrades from 5.1% to 1.2% as the pumping power reduces from 85 to 24 mW, which is attributed to the saturable absorption of the few-layer graphene-based evanescent-wave absorber. The modulation depth at wavelength of 1550 nm under a probe power of 1 mW increases from 1.2% to 5.1%, as more carriers can be excited when increasing the blue laser power from 24 to 85 mW, whereas it decreases from 5.1% to 3.3% by increasing the input probe power from 1 to 2 mW to show an easier saturated condition at longer wavelength.

【 授权许可】

CC BY