论文标题
波长和时间分割通过脉冲半导体激光器的泵电流变化 - 一种用于量子键分布的同步方法
Wavelength- and time-division multiplexing via pump current variation of a pulsed semiconductor laser -- a method of synchronization for quantum key distribution
论文作者
论文摘要
半导体激光波长对泵电流的依赖性是众所周知的现象，这通常归因于由于载体注入而导致的活性层折射率的变化。这种效果通常被认为是一个缺点，因为它会导致通过直流电流调制产生的脉冲的频率chi。在这里，我们表明，在激光二极管的热电阻值高值下，由于由热效应引起的折射率的变化，激光波长是红移的，并且这种偏移可能会显着超过与载体注入引起的折射率变化相关的蓝移。我们建议通过泵电流变化来调整波长的能力，并使用相同的激光生成量子和同步光脉冲，以在不同波长的情况下以量子键分布。为了证明提出的同步方法，我们执行数值模拟以及原则实验。
The dependence of the semiconductor laser wavelength on the pump current is a well-known phenomenon, which is generally attributed to a change in the refractive index of the active layer due to carrier injection. This effect is usually considered to be a drawback as it causes frequency chirping of the pulses produced via direct current modulation. Here, we show that at high values of thermal resistance of a laser diode, the lasing wavelength is red-shifted due to the change of the refractive index caused by a thermal effect and this shift may significantly exceed (in absolute value) the blue shift related to a refractive index change induced by the carrier injection. We propose to benefit from the ability to tune wavelength by the pump current variation and use the same laser to generate qubits and synchronization optical pulses for quantum key distribution at different wavelengths. To demonstrate the proposed method of synchronization, we perform numerical simulations as well as proof-of-principle experiments.
