Polarization and Thickness Dependent Absorption Properties of Black Phosphorus: New Saturable Absorber for Ultrafast Pulse Generation.
Polarization and Thickness Dependent Absorption Properties of Black Phosphorus: New Saturable Absorber for Ultrafast Pulse Generation.
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DOI：
10.1038/srep15899
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发表时间：
2015-10-30
影响因子：
4.6
通讯作者：
Sun Z
中科院分区：
文献类型：
--
作者：
Li D;Jussila H;Karvonen L;Ye G;Lipsanen H;Chen X;Sun Z
黑磷(BP)由于其独特的电学和光学性质，最近被重新发现为一种新的有趣的二维材料。在这里，我们研究了BP薄片的线性和非线性光学性质。我们观察到线性和非线性光学性质都是各向异性的，并且可以通过BP中的薄膜厚度来调节，这与其他典型的二维层状材料(例如石墨烯和研究最多的过渡金属二卤化物)完全不同。然后利用BP的非线性光学特性，在近红外通信波段~1.5 m的光纤激光器中产生超快脉冲(锁模脉冲宽度可达~786 fs)和大能量脉冲(调Q脉冲能量可达~18 μnJ)。由于BP的各向异性光学特性，我们观察到基于BP的脉冲激光器的输出是线偏振的(锁模时偏振度为~98%，调Q时为>；99%)。我们的结果强调了BP具有相对较大的光学非线性，具有独特的偏振和厚度相关性，以及它在产生偏振光脉冲方面的潜力，为基于BP的非线性和超快光子应用(例如，超快全光偏振开关/调制器、变频器等)铺平了道路。
Black phosphorus (BP) has recently been rediscovered as a new and interesting two-dimensional material due to its unique electronic and optical properties. Here, we study the linear and nonlinear optical properties of BP flakes. We observe that both the linear and nonlinear optical properties are anisotropic and can be tuned by the film thickness in BP, completely different from other typical two-dimensional layered materials (e.g., graphene and the most studied transition metal dichalcogenides). We then use the nonlinear optical properties of BP for ultrafast (pulse duration down to ~786 fs in mode-locking) and large-energy (pulse energy up to >18 nJ in Q-switching) pulse generation in fiber lasers at the near-infrared telecommunication band ~1.5 μm. We observe that the output of our BP based pulsed lasers is linearly polarized (with a degree-of-polarization ~98% in mode-locking, >99% in Q-switching, respectively) due to the anisotropic optical property of BP. Our results underscore the relatively large optical nonlinearity of BP with unique polarization and thickness dependence, and its potential for polarized optical pulse generation, paving the way to BP based nonlinear and ultrafast photonic applications (e.g., ultrafast all-optical polarization switches/modulators, frequency converters etc.).