A Novel Gold Film-Coated V-Shape Dual-Core Photonic Crystal Fiber Polarization Beam Splitter Covering the E + S + C + L + U Band

oleh: Yuwei Qu, Jinhui Yuan, Shi Qiu, Xian Zhou, Feng Li, Binbin Yan, Qiang Wu, Kuiru Wang, Xinzhu Sang, Keping Long, Chongxiu Yu

Format: Article
Diterbitkan: MDPI AG 2021-01-01

Deskripsi

In this paper, a novel gold film-coated V-shape dual-core photonic crystal fiber (V-DC-PCF) polarization beam splitter (PBS) based on surface plasmon resonance effect is proposed. The coupling lengths of the X-polarization (X-pol) and Y-polarization (Y-pol) and the corresponding coupling length ratio of the proposed V-DC-PCF PBS without gold film and with gold film are compared. The fiber structure parameters and thickness of the gold film are optimized through investigating their effects on the coupling lengths and coupling length ratio. As the propagation length increases, the normalized output powers of the X-pol and Y-pol of the proposed V-DC-PCF PBS at the three wavelengths 1.610, 1.631, and 1.650 <inline-formula><math display="inline"><semantics><mrow><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">m</mi></mrow></semantics></math></inline-formula> are demonstrated. The relationships between the extinction ratio (<inline-formula><math display="inline"><semantics><mrow><mi>E</mi><mi>R</mi></mrow></semantics></math></inline-formula>), insertion loss (<inline-formula><math display="inline"><semantics><mrow><mi>I</mi><mi>L</mi></mrow></semantics></math></inline-formula>) and wavelength for the three splitting lengths (<inline-formula><math display="inline"><semantics><mrow><mi>S</mi><mi>L</mi><mi>s</mi></mrow></semantics></math></inline-formula>) 188, 185, and 182 <inline-formula><math display="inline"><semantics><mrow><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">m</mi></mrow></semantics></math></inline-formula> are investigated. Finally, it is demonstrated that for the proposed V-DC-PCF PBS, the optimal <inline-formula><math display="inline"><semantics><mrow><mi>S</mi><mi>L</mi></mrow></semantics></math></inline-formula> is 188 <inline-formula><math display="inline"><semantics><mrow><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">m</mi></mrow></semantics></math></inline-formula>, the <inline-formula><math display="inline"><semantics><mrow><mi>I</mi><mi>L</mi><mi>s</mi></mrow></semantics></math></inline-formula> of the X-pol and Y-pol are less than 0.22 dB, and the splitting bandwidth (<inline-formula><math display="inline"><semantics><mrow><mi>S</mi><mi>B</mi></mrow></semantics></math></inline-formula>) can cover the E + S + C + L + U band. The proposed V-DC-PCF PBS has the ultra-short <inline-formula><math display="inline"><semantics><mrow><mi>S</mi><mi>L</mi></mrow></semantics></math></inline-formula>, ultra-wide <inline-formula><math display="inline"><semantics><mrow><mi>S</mi><mi>B</mi></mrow></semantics></math></inline-formula>, and ultra-low <inline-formula><math display="inline"><semantics><mrow><mi>I</mi><mi>L</mi></mrow></semantics></math></inline-formula>, so it is expected to have important applications in the laser, sensing, and dense wavelength division multiplexing systems.