Recently, the research team led by TONG Cunzhu from the Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, has made significant progress in the field of photonic crystal surface emitting lasers (PCSELs). The team proposed a novel triple-lattice structure and successfully achieved low-threshold operation of PCSELs at 1.55 μm.

These findings were published in Light: Science & Applications. The renowned international semiconductor industry journal, Semiconductor Today, featured the breakthrough with a news article titled "Triple-lattice photonic crystal laser".

The publication notes that the 1.55 μm range transmits though optical fiber with minimum loss, and features eye-safety up to higher power. However, traditional lasers suffer from poor performance due to high interband absorption in this range. The PCSEL structure can deliver strong optical feedback to overcome this, reducing thresholds and improving output power.

Based in the United Kingdom, Semiconductor Today is a distinguished magazine and website in the global semiconductor industry, dedicated to reporting on significant advancements in research and the latest industry developments. It holds substantial influence within the sector.

PCSELs represent a pivotal research direction currently receiving substantial attention in the semiconductor laser domain, with potential broad applications across multiple technological fields including communication transmission, laser pumping, optical sensing, and medical device technologies, being defined as a core root technology by leading industry giants. Nevertheless, their practical implementation in areas such as high-speed optical communications remains unattainable due to the limitations imposed by large device dimensions and high threshold currents.

This work pioneers the proposition of employing a triple-lattice photonic crystal structure to enhance optical feedback within the resonant cavity and, based on this concept, fabricates an InP-based, continuous electrically pumped PCSEL operating at the 1.55 μm wavelength band.

This development introduces a new approach for downsizing photonic crystal cavities and lowering the threshold current of such devices, thereby contributing in their future applications like high-speed optical communication systems and LiDAR technology.