近日，日本京都大学Noda, Susumu团队研究了用于远距离相干自由空间光通信的调频高功率光子晶体表面发射激光器。相关论文发表在2025年10月14日出版的《自然—光子学》杂志上。

高功率、高速可控的相干光学发射器在星间通信、深空光通信等前沿应用领域需求迫切。传统发射器除半导体激光源外还需配备光纤放大器、外部相位调制器、光学光纤与光束准直透镜等诸多笨重光学元件，这成为实现系统小型化与高效化的主要障碍。

研究组提出并实验验证了基于频率调制光子晶体表面发射激光器的紧凑型相干光学发射器，旨在实现长距离自由空间光通信。他们设计出集成双光子晶体的双段结构PCSEL，其光子晶体具有略微差异的带边共振频率，通过向两段注入反相电流，实现了振幅调制受抑制的瓦级频率调制。

以上述双段PCSEL作为相干光学发射器，研究组演示了即使在激光功率衰减超过80 dB时仍具备Gbps级带宽的无光纤放大器自由空间光通信。这项研究为实现单片集成相干光学发射器开辟了新途径，其体积与重量较传统笨重系统可缩小数个数量级，适用于多种相干自由空间激光应用场景。

附：英文原文

Title: Frequency-modulated high-power photonic-crystal surface-emitting lasers for long-distance coherent free-space optical communications

Author: Inoue, Takuya, Morita, Ryohei, Ishimura, Shota, Nakano, Shuei, Takahashi, Hidenori, Tsuritani, Takehiro, De Zoysa, Menaka, Ishizaki, Kenji, Suzuki, Masatoshi, Noda, Susumu

Issue&Volume: 2025-10-14

Abstract: High-power coherent optical transmitters with high-speed controllability are in demand for a number of cutting-edge applications, including intersatellite communications and deep-space optical communications. The conventional transmitters used in these applications require many bulky optical components besides their semiconductor laser sources, such as fibre-optical amplifiers, external phase modulators, optical fibres and beam-collimation lenses, which are obstacles in achieving compact and efficient systems. Here we propose and experimentally demonstrate compact coherent optical transmitters based on frequency-modulated photonic-crystal surface-emitting lasers (PCSELs) towards achieving long-distance free-space optical (FSO) communications. We design two-section PCSELs that incorporate two photonic crystals with slightly different band-edge resonant frequencies, and we realize watt-class frequency modulation with suppressed amplitude modulation via anti-phase current injection into the two sections. Using the above two-section PCSELs as coherent optical transmitters, we demonstrate fibre-amplifier-free FSO communications with Gbps-class bandwidth, even when the laser power is attenuated by >80dB. Our work opens avenues toward the realization of one-chip coherent optical transmitters whose volume and weight are several orders of magnitude smaller than conventional bulky systems for a wide variety of coherent free-space laser applications.

DOI: 10.1038/s41566-025-01782-2

Source: https://www.nature.com/articles/s41566-025-01782-2