Source: Ferdinand-Braun-Institut

Broad Area Laser Diodes: A Comprehensive Overview

Introduction

Broad area laser diodes, also known as broad stripe or high brightness diode lasers, are edge-emitting laser diodes with a broad emitting region at the front facet. These diodes exhibit asymmetric beam properties, resulting in unique characteristics in different directions.

Asymmetric Beam Properties

Broad area laser diodes have a narrow height in the vertical direction, leading to single-mode guidance and excellent beam quality with high divergence. In contrast, the horizontal direction features a wider stripe width, causing the light to be distributed over multiple spatial modes and resulting in larger beam divergence.

Technological Advancements

The power output of broad area laser diodes increases with the width of the emitting stripe. However, achieving higher powers is limited by optical intensity and thermal issues. Facet passivation techniques are employed to enhance power output. Commercial devices typically offer a few watts to tens of watts of output power across different wavelength regions.

Special Features

Some broad area laser diodes come with integrated features like fast axis collimation lenses and Bragg gratings for wavelength stabilization. Tapered laser diodes are designed to improve beam quality and brightness, making them suitable for various applications.

Applications

Broad area laser diodes are commonly used for pumping solid-state and fiber lasers in laser material processing applications. Their tunable emission wavelength and high power output make them versatile for different laser systems.

Comparison with Diode Bars

Diode bars, which consist of multiple broad area emitters, offer higher output power but lower brightness compared to single-emitter lasers. Broad-area diodes are preferred for pumping high-power lasers due to their ability to be turned on and off without affecting lifetime.

Conclusion

Broad area laser diodes play a crucial role in various laser applications, offering a balance between power output and beam quality. Advancements in technology continue to improve the performance and versatility of these diodes in different laser systems.

By understanding the unique properties and applications of broad area laser diodes, researchers and industry professionals can harness their capabilities for a wide range of photonics applications.

Source: Ferdinand-Braun-Institut
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