Proceedings Article | 15 March 2023
KEYWORDS: Semiconductor lasers, Quantum technologies, Reliability, Red lasers, Quantum wells, Diodes, Mercury laser cooling, Optical lattice clocks, Strontium
In recent years, red Laser Diodes (LDs), especially, longer wavelengths of “deep red” have been used in the biomedical and quantum technology fields. In light-based cancer therapies such as Photodynamic Therapy (PDT) and near-infrared photoimmunotherapy (NIR-PIT), and in skin care, high power red LDs are required. We have demonstrated highly reliable 1.2 W multi-mode LDs with the wavelength of 630, 635, 652, 659, 665, 675, 683, and 690 nm. Life test results showed stable operation in 2,700 hours at 20°C, 1.2 W for 630 nm LD, and in 10,000 hours at 75°C, 1.2 W for 675 and 690 nm LDs. These multi-mode LDs are suitable for fiber coupling because of their small emitter size of 80μm, and high power and high reliability make them ideal light sources for biomedical applications. In addition, deep red high power single-mode LDs are desired for optical lattice clocks and laser cooling. We have demonstrated AlGaInP-based 200 mW single-mode LDs with the wavelength of 690, 700, and 705 nm. Life test results showed stable operation in 4,000 hours at 75°C, 200 mW for all three wavelengths. Of all AlGaInP-based material, the 705 nm LD which demonstrated reliable operation is the world’s longest wavelength LD to the best of our knowledge. These single-mode LDs wavelength can be adjusted for the specific value by controlling temperature, which makes them ideal light sources for quantum technology. We believe that these new light sources will contribute to solving social challenges and explore the future.
