659 nm Biomedical Red Laser Diode Reaches Highest Power Ever

Phototherapy devices downsize with world record CW optical output power of 1.2 W

Ushio Opto Semiconductors, Inc. (Head Office: Tokyo, Managing Executive Officer: Hiroaki Banno), a wholly-owned subsidiary of Ushio, Inc., released a 659 nm red laser diode (LD) (HL65213HD) for biomedical use in October 2019, which achieves a continuous wave (CW) optical output power of 1.2 W^*1, a world record for its class.

Demand for high output power laser diodes around the 660 nm wavelength range has increased in medical fields such as DNA sequencing and phototherapy, and life science applications such as laser microscopy and Raman spectroscopy. Red laser diodes emitting wavelengths in this region can cause a photochemical reaction in materials (e.g., melanin and haemoglobin) that absorb these wavelengths with high efficiency and in a short time.

These applications require watt-level output power, but the output power of the LDs in this wavelength range is usually at the milliwatt (mW) level. Until now, to achieve a watt-level output power, multiple LDs have been deployed as modules in a single system by connecting them with optical fibres. The downside of this technique is that systems become larger and more expensive to construct.

Crystal growth technology secures laser advancement at 659 nm

To address this problem, Ushio Opto Semiconductors has successfully developed a highly reliable multi-mode LD^*2, which achieves a CW optical output power of 1.2 W in the 659 nm wavelength range. This technological leap was accomplished by combining the crystal growth technology accumulated through the development and commercialisation of LDs for use in sensors in the 660 nm wavelength range, as well as the watt-level high output power LD process and packaging technology cultivated in the 640 nm wavelength range.

This new laser solution is expected to be adopted in various fields, since it helps reduce the size of various systems.

HL65213HD Features:

1. The world’s highest CW optical output power of 1.2 W achieved in a 9 mm package. High heat dissipation and air-tightness ensure high reliability and help reduce the size and cost of the light source unit. CW optical output power of 1.2 W and pulse optical output power of 1.5 W were achieved at operating temperatures from -10°C to 25°C. CW optical output power of 1.0 W and pulse optical output power of 1.3 W were achieved at a maximum temperature of 45°C.
2. The world’s highest wall plug efficiency of 39%^*3 was achieved and lower power consumption helps simplify the cooling system.

Specifications:

(Operating temperature Tc=25℃)

^*1 The world’s highest optical output power from a single CAN package (as of September 2019 according to Ushio Opto Semiconductors’ research data)

^*2 LD that has multiple oscillation modes in a waveguide, which is ideal for increasing output power.

^*3 Ratio of optical output power to input power (operating temperature of 25°C during CW operation)