High beam quality, high brightness dense spectral beam combining of 650 nm laser diode module

Area of Science:

• Optics and Photonics
• Laser Technology

Background:

• Laser diode modules are crucial for various applications.
• Achieving high power and brightness from laser diodes remains a challenge.
• Dense spectral beam combining (DSBC) offers a potential solution for power scaling.

Purpose of the Study:

• To demonstrate dense spectral beam combining (DSBC) for a 650 nm laser diode module for the first time.
• To determine the optimal spectral locking interval for 650 nm wavelength band.
• To enhance the output power and beam brightness of laser diodes.

Main Methods:

• Stimulation was used to obtain the optimal spectral locking interval for the 650 nm band.
• A DSBC device with 19 single emitters was designed and constructed based on the optimal interval.
• Output power, spectral width, beam quality (M²), and beam brightness were measured.

Main Results:

• The DSBC device achieved an output power of 17.74 W with a stable spectral width of 4.75 nm.
• Beam quality factors (M²) were comparable to single emitters, with slight optimization in the slow-axis.
• The beam brightness reached 123.395 MW·cm⁻²·sr⁻¹, a fourteenfold increase over single emitters.

Conclusions:

• DSBC is a viable technique for significantly increasing the power and brightness of 650 nm laser diodes.
• The developed DSBC system demonstrates a substantial improvement in laser performance.
• This advancement has implications for applications requiring high-brightness laser sources.