Semiconductor Laser Engineering, Reliability and Diagnostics: A Practical Approach to High Power and Single Mode Devices

Chapter 5

Basic reliability engineering concepts

5.1 Descriptive reliability statistics

5.1.1 Probability density function

5.1.2 Cumulative distribution function

5.1.3 Reliability function

5.1.4 Instantaneous failure rate or hazard rate

5.1.5 Cumulative hazard function

5.1.6 Average failure rate

5.1.7 Failure rate units

5.1.8 Bathtub failure rate curve

5.2 Failure distribution functions – statistical models for nonrepairable populations

5.2.1 Introduction

5.2.2 Lognormal distribution

5.2.3 Weibull distribution

5.2.4 Exponential distribution

5.3 Reliability data plotting

5.3.1 Life-test data plotting

5.4 Further reliability concepts

5.4.1 Data types

5.4.2 Confidence limits

5.4.3 Mean time to failure calculations

5.4.4 Reliability estimations

5.5 Accelerated reliability testing – physics–statistics models

5.5.1 Acceleration relationships

5.5.2 Remarks on acceleration models

5.6 System reliability calculations

5.6.1 Introduction

5.6.2 Independent elements connected in series

5.6.3 Parallel system of independent components

References

Introduction

In the previous chapters, we described aspects of design and fabrication technology aimed at maximizing the performance and reliability of diode lasers. Reliability-related aspects included optical strength of laser materials, optimum design of transverse vertical and lateral waveguide structures, and optically robust mirror technologies. Reliability has to be an integral part of all phases of the laser product cycle, from product proposal, ...