Hamamatsu develops ‘record’ 2.0 kW laser diode bar

Hamamatsu Photonics has achieved what it calls “world-class” quasi-continuous wave output of 2.0 kW from a 1 cm-wide laser diode (LD) bar at room temperature. Quasi-continuous wave (QCW) is a mode of operation in which light is emitted in relatively long pulse width – such as above 100 µs – at high repetition rates, exhibiting characteristics intermediate between continuous-wave and ns pulsed operation, the company explained.

 This capability is expected to expand applications of high-power lasers, including industrial laser processing equipment and pump sources for solid-state lasers, as well as enable future deployment in advanced fields requiring high-energy light sources.

The development work was conducted under a project commissioned by Japan’s New Energy and Industrial Technology Development Organization (NEDO) as part of its “NEDO Feasibility Study Program / Frontier Incubation Program.” The results are scheduled to be presented at the 30th International Semiconductor Laser Conference 2026, to be held in Tampere, Finland, from June 14-17, 2026, in the session “Workshop Session 1: Advances in Semiconductor Laser Industry.”

How laser diodes work

An LD bar is a light-emitting device formed by arranging multiple LD emitters in an array. Together with stacked configurations known as LD bar stacks, these devices are widely used in industrial applications such as laser processing. In particular, since a large number of LD bars are required for pumping high-power and high-energy solid-state lasers, there is a strong demand for higher output power from individual LD bars.

High-output power LDs are expected not only to enable more compact and energy-efficient laser systems for conventional material processing, but also to contribute to advancements in manufacturing processes for products in advanced fields requiring high-energy light sources, as well as to expand applications in areas such as space and advanced scientific research.

Hamamatsu commented, “We have been working to increase the output power of LD bars by optimizing crystal structures, device designs, crystal growth techniques, and assembly technologies. In addition, through commissioned research under the FY2025 NEDO Feasibility Study Program / Frontier Incubation Program, we have advanced facet treatment technologies to suppress degradation at the LD facets.

“To the best of our knowledge, this exceeds the previous record of 1.9 kW at room temperature reported by a German research institute in 2022, representing a world-record level achievement. Going forward, we will build on this result and accelerate R&D of multi-junction LD bars to achieve even higher output power.

[A multi-junction LD bar is a structure in which multiple semiconductor PN junctions are stacked, enabling higher optical output.]

“Through this research, we aim to achieve extreme power scaling of laser diodes (LDs) and contribute to the creation of new industries based on power lasers by 2040. In parallel, we will explore new applications throughout the process and pursue early commercialization.”