A Study on the Indium Gallium Nitride Laser

Abstract

Indium Gallium Nitride (InGaN) lasers are semiconductor lasers. Because the human eye perceives the light\'s wavelength as blue, it is also known as a blue laser. Indium nitride (InN) and gallium nitride (GaN) are combined to create InGaN, which is basically a semiconductor material. By altering the indium content, the band gap of this substance can be adjusted. [22]

Introduction

A laser (Light Amplification by Stimulated Emission of Radiation) is a device that emits coherent, focused, and monochromatic light through the process of stimulated emission. The first laser was developed in 1960 by Theodore Maiman, building on theoretical work by Townes and Schawlow. Lasers are unique because of their spatial coherence, which allows them to focus into tiny spots or stay narrow over long distances, and temporal coherence, which enables narrow frequency output or extremely short pulses.

Lasers have a wide range of applications including cutting and welding, communications, barcode scanning, printers, CD/DVD systems, medical surgery, skin treatments, photolithography, scientific research, and even automotive lighting. The earlier devices that operated using similar principles at microwave frequencies were called masers, and lasers evolved from these concepts.

The history of lasers began with Einstein’s 1916 theory of stimulated emission. Important milestones include the development of masers by Townes, Basov, and Prokhorov (Nobel Prize 1964), and later the first optical laser by Maiman with a ruby crystal. Subsequent breakthroughs included helium–neon lasers, semiconductor lasers, and holography.

Principle of Laser Operation

Laser action is based on population inversion—a condition where more atoms occupy an excited energy state than the ground state. When a photon with the correct energy passes through, it triggers stimulated emission, producing identical photons. This chain reaction occurs inside a resonant cavity formed by mirrors, amplifying the light into a coherent beam. Laser systems typically involve three-level or four-level energy structures, with four-level designs supporting continuous output.

Characteristics of Laser Beams

Laser beams are:

• Highly focused

• Monochromatic (single wavelength)

• Coherent (phase-aligned)

• Collimated (low divergence)

The beam properties depend on the gain medium, resonant cavity, and stimulated emission process. Laser output may be continuous or pulsed, with some pulsed lasers reaching extremely high instantaneous powers for femtosecond durations.

InGaN (Indium Gallium Nitride) Lasers

InGaN lasers are semiconductor blue lasers made from gallium nitride and indium nitride. By varying indium concentration, their band gap—and thus wavelength—can be tuned. They operate in the 0.4–0.5 µm wavelength range and are powered by electric discharge.

Conclusion

Semiconductor lasers are known as indium gallium nitride (InGaN) lasers. Because the human eye perceives the light\'s wavelength as blue, it is also known as a blue laser. InGaN, which is essentially a semiconductor material, is made by combining indium nitride (InN) and gallium nitride (GaN). This material\'s band gap can be changed by varying its indium content. [22]

References

[1] Taylor, Nick (2000). Laser: The Inventor, The Nobel Laureate, and The Thirty-Year Patent War. Simon & Schuster. p. 66. ISBN 978-0684835150. [2] Ross T., Adam; Becker G., Daniel (2001). Proceedings of Laser Surgery: Advanced Characterization, Therapeutics, and Systems. SPIE. p. 396. ISBN 978-0-8194-3922-2. [3] \"December 1958: Invention of the Laser\". aps.org. Archived from the original on December 10, 2021. Retrieved January 27, 2022 [4] Semiconductor Sources: Laser plus phosphor emits white light without droop\". November 7, 2013. Archived from the original on June 13, 2016. Retrieved February 4, 2019. [5] Laser Lighting: White-light lasers challenge LEDs in directional lighting applications\". February 22, 2017. Archived from the original on February 7, 2019. Retrieved February 4, 2019. [6] How Laser-powered Headlights Work\". November 7, 2011. Archived from the original on November 16, 2011. Retrieved February 4, 2019. [7] Laser light for headlights: Latest trend in car lighting | OSRAM Automotive\". Archived from the original on February 7, 2019. Retrieved February 4, 2019. [8] Heilbron, John L. (March 27, 2003). The Oxford Companion to the History of Modern Science. Oxford University Press. pp. 447. ISBN 978-0-19-974376-6. [9] Bertolotti, Mario (October 1, 2004). The History of the Laser. CRC Press. pp. 215, 218–219. ISBN 978-1-4200-3340-3. [10] McAulay, Alastair D. (May 31, 2011). Military Laser Technology for Defense: Technology for Revolutionizing 21st Century Warfare. John Wiley & Sons. p. 127. ISBN 978-0-470-25560-5. [11] Renk, Karl F. (February 9, 2012). Basics of Laser Physics: For Students of Science and Engineering. Springer Science & Business Media. p. 4. ISBN 978-3-642-23565-8. [12] LASE\". Collins Dictionary. Retrieved January 6, 2024. [13] \"LASING\". Collins Dictionary. Retrieved January 6, 2024. [14] Strelnitski, Vladimir (1997). \"Masers, Lasers and the Interstellar Medium\". Astrophysics and Space Science. 252: 279–287. Bibcode:1997Ap&SS.252..279S. doi:10.1023/ [15] Chu, Steven; Townes, Charles (2003). \"Arthur Schawlow\". In Edward P. Lazear (ed.). Biographical Memoirs. Vol. 83. National Academy of Sciences. p. 202. ISBN 978-0-309-08699-8 [16] Al-Amri, Mohammad D.; El-Gomati, Mohamed; Zubairy, M. Suhail (December 12, 2016). Optics in Our Time. Springer. p. 76. ISBN 978-3-319-31903-2. [17] Hecht, Jeff (December 27, 2018). Understanding Lasers: An Entry-Level Guide. John Wiley & Sons. p. 201. ISBN 978-1-119-31064-8. [18] https://www.ulsinc.com/learn [19] https://www.fiberoptics4sale.com/blogs/wave-optics/semiconductor-laser-physics [20] https://www.szlaser.com/index.php/wiki/laser-physics/ [21] https://www.britannica.com/technology/laser [22] [https://www.azooptics.com/Article.aspx?ArticleID=517

Copyright

Copyright © 2025 Muhammad Arif Bin Jalil. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.