Perrone Sandro, Vilaseca Ramon, Masoller Cristina
Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Colom 11, 08222 Terrassa, Spain.
Opt Express. 2012 Sep 24;20(20):22692-9. doi: 10.1364/OE.20.022692.
We study numerically the dynamics of a vertical-cavity surface-emitting laser (VCSEL) with optical injection and show that the interplay of polarization bistability and noise yields a reliable logic output to two logic inputs. Specifically, by encoding the logic inputs in the strength of the light injected into the suppressed polarization mode of the VCSEL (the so-called 'orthogonal' injection), and by decoding the output logic response from the polarization state of the emitted light, we demonstrate an all-optical stochastic logic gate that exploits the ubiquitous presence of noise. It gives the correct logic output response for as short as 5 ns bit times when the dimensionless spontaneous emission coefficient, β(sp), is within the range 10(-4)-10(-1). Considering that typical values of β(sp) in semiconductor lasers are in the range 10(-5)-10(-4), the VCSEL-based logic gate can be implemented with nowadays commercially available VCSELs, exploiting either their intrinsic noise, or external and background noise sources.
我们通过数值研究了具有光注入的垂直腔面发射激光器（VCSEL）的动力学，并表明偏振双稳性和噪声的相互作用为两个逻辑输入产生了可靠的逻辑输出。具体而言，通过将逻辑输入编码到注入到VCSEL抑制偏振模式（所谓的“正交”注入）的光强度中，并通过从发射光的偏振态解码输出逻辑响应，我们展示了一种利用普遍存在的噪声的全光随机逻辑门。当无量纲自发发射系数β(sp)在10^(-4)-10^(-1)范围内时，它在短至5 ns的比特时间内给出正确的逻辑输出响应。考虑到半导体激光器中β(sp)的典型值在10^(-5)-10^(-4)范围内，基于VCSEL的逻辑门可以利用其固有噪声或外部和背景噪声源，用当今商用的VCSEL来实现。
