高功率半导体激光器1/f噪声特性及其检测新方法研究

We will investigate the characteristics in high-power semiconductor laser diodes (LDs) at low bias currents for the high-current particularity of high-power LDs. The device reliability will be analyzed from the active region and the creepage resistance based on the magnitude and its variety trend of 1/f noise magnitude vs the bias current, and then comparing them with the data from electrical aging for devices, the quantitative relation between the reliability and the characteristics of 1/f noise in high-power LDs can be achieved. According to the particularities of 'self similarity' and 'long-range relativity' of 1/f-type fractal signal, the compressive sensing theory will be applied to the estimation of 1/f noise and its parameters, and by constructing the random measurement matrix and the sensing matrix from the less acquired data, it can be achieved to separate the 1/f noise and additive white noise so that an effective method to estimate the parameters and waveform of 1/f noise can be established. Based on that, we will develop the intelligent detection system of low-frequency electrical noise of high-power LDs to conquer the detection disadvantages of wavelet transformation such as low efficiency and needed much data. On the basis of the above investigation, the integrative reliability estimation and invalidation of LDs can be achieved, and at last, a fast, nondestructive and effective system to estimate the LDs reliability can be established.

针对大功率半导体激光器工作电流大的特殊性，重点研究其低偏置电流下的1/f噪声特性，用其幅度的大小及其随偏置电流的变化趋势，从器件的有源区和漏电特性的角度来分析器件的可靠性，继而与器件的老化实验数据进行对比，从而进一步建立高功率半导体激光器1/f噪声特性与器件可靠性的定量关系；根据1/f类分形信号的"自相似"和"长程相关性"的特点，把压缩传感技术用于1/f噪声参数的估计，构造其随机测量矩阵和传感矩阵，在较少的数据采集量的情况下，实现1/f噪声与加性白噪声的分离，最终建立一种有效的1/f噪声波形及其参数的估计方法，在此基础上，开发大功率半导体激光器低频电噪声的智能检测系统，从而克服传统的基于小波变换检测方法的效率低、所需数据量大的缺点；在上述基础上，最终实现高功率半导体激光器的可靠性进行综合估计和失效分析，建立一种快速、无损、有效的可靠性智能评价系统。

大功率半导体激光器作为一种重要的光源器件，在工业、医学、军事以及信息技术等高新技术领域得到了广泛应用，本项目开展高功率半导体激光器1/ƒ噪声特性及其检测新方法研究，以建立1/f噪声特性与器件可靠性的密切关系，实现大功率半导体激光器可靠性的一种无损检测方法。搭建了半导体激光器1/f噪声的直接测量系统和数字测量系统，解决噪声测量过程中的器件及偏置电路的屏蔽问题，实现了1/f噪声的准确测量。开展了1/ƒ噪声计算机合成方法的研究，获得1/f噪声及其参数估计研究的所需纯净的信号源。研究了低偏置电流下各个半导体激光器1/ƒ噪声幅度随注入电流的变化规律，验证了用噪声相关性替代传统方法中的噪声幅值作为分析参数更具有实用性和优势。开发了高功率半导体激光器的变步长扫描电流下的电导数的测量系统，为半导体激光器1/ƒ噪声提供了对比和参考数据。研究了电老化器件的1/f噪声特性，通过与电导数的初始峰的对比，发现1/f噪声强度与器件内部缺陷、腔面损伤及表面漏电等因素有密切的关系，从而进一步验证了1/f噪声特性评价半导体激光器可靠性的可行性。