Note: Coupling of multiple laser diodes into a multi-mode fiber.

Area of Science:

• Optics and Photonics
• Laser Technology
• Fiber Optics

Background:

• Diode lasers are crucial light sources with diverse applications.
• Efficiently coupling diode laser light into optical fibers is essential for power delivery.
• Existing coupling methods can be limited in efficiency and flexibility.

Purpose of the Study:

• To develop an optimized optical setup for coupling diode lasers into multi-mode fibers.
• To investigate the use of a pyramidal reflector for enhanced light coupling.
• To demonstrate the power delivery capabilities of the system for various laser wavelengths.

Main Methods:

• Utilized a regular pyramid-shaped reflector for diode laser coupling.
• Optimized the optical setup to maximize light coupling efficiency into multi-mode fibers (100-400 μm core).
• Tested the system with multiple diode laser wavelengths: violet (405 nm), blue (445 nm), and red (638 nm).

Main Results:

• Achieved 60%-90% light coupling efficiency into the optical fiber.
• Demonstrated power outputs of 3.5 W (violet), 5.5 W (blue), and 3.3 W (red) in specified fiber core sizes.
• Confirmed functionality with frequency-doubled green (532 nm) lasers.

Conclusions:

• The pyramidal reflector-based optical setup enables highly efficient diode laser coupling into multi-mode fibers.
• The system demonstrates robust performance across a range of visible laser wavelengths.
• This technology holds potential for medical applications requiring high-power, wavelength-tunable laser sources.