Source: Coherent

Understanding Diode Bars in Semiconductor Lasers

Introduction

Diode bars are high-power semiconductor lasers that consist of an array of emitters. They are widely used in various applications due to their efficiency and power output capabilities.

Design and Operation

Diode bars contain multiple emitters that can generate tens to hundreds of watts of power. The use of arrays prevents issues like amplified spontaneous emission and ensures a stable mode profile. Techniques like coherent coupling improve beam quality.

Emission Wavelengths and Bandwidth

Most diode bars operate in the range of 780 to 860 nm or 940 to 980 nm. These wavelengths are crucial for applications such as pumping neodymium and Yb:YAG lasers.

Spatial Beam Properties and Collimation

Diode bars exhibit different beam qualities in the fast and slow axis directions. Special collimators are used to ensure proper beam quality and collimation. Beam shaping techniques help in symmetrizing the beam quality.

Fiber Coupling

Many diode bars are fiber-coupled for easy integration and distance mounting. Fiber coupling allows efficient utilization of the laser output and is common in various laser systems.

Cooling and Power Efficiency

Diode bars require effective cooling systems to maintain performance and longevity. They operate with high power efficiency, typically around 50%, with ongoing developments to improve efficiency and reduce power consumption.

Lifetime and Applications

Under ideal conditions, diode bars can have long lifetimes. They find applications in laser material processing, medical treatments, military technologies, and pumping high-power solid-state lasers.

Conclusion

Diode bars play a crucial role in various laser applications, offering high power output, efficiency, and reliability. Ongoing advancements in technology aim to enhance their performance and expand their applications in different industries.

Source: YouTube
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