基于直接泵浦腔内光参量变频技术的脑微创手术所需6.45μm固体激光产生基础问题研究

Brain Tumor is a common but extremely dangerous disease, for it destroys human’s nervous system or even kills their lives. It’s timely detection and completely ablation are very important. While the collateral damage to the nerve, the vessels, the health tissues and etc during surgical dissection of cancer tissue may lead the patients disabled or even loss their lives, so the viability of the remaining tissue is of great importance in ablation. 6.45 µm laser has tremendous potential as high-precision surgical tools, as it offers tissue ablation a minimal collateral damage and a substantial ablation rate. The penetration depth at this wavelength amounts to several µm which is comparable to the cell size, i.e. close to the optimum value, and it is useful for human surgery. Then the investigation of 6.45 µm laser with high power and high pulse energy has become a cutting edge current research. This project proposed a intracavity direct frequency conversion design, based on solid state laser, for the realization of 6.45 µm laser. Compared with existing teleology, the FEL and extracavity optical frequency conversion lasers, the intracavity direct frequency conversion design takes full use of the intense energy in the fundamental laser cavity, which may offer a potential design for high power and high pulse energy 6.45 µm laser generation that satisfies the clinical application demands. In addition, this design has a compact structure and is more suitable for clinical application. By detailed investigation of fundamental problems in 6.45 μm solid laser generation, and breaking through on key technology, this project lays the foundation of research and development for 6.45 μm laser medical equipment.

脑瘤严重影响人类神经系统的功能及生命，其及时发现与清除极为重要，但手术过程中对重要功能区的神经中枢、血管、组织等的附带损伤将直接影响患者生命、或相关组织功能完整性。6.45μm激光可作为激光刀对病变组织进行高精度切除的同时实现毗邻结构最小附带损伤，其切除精度可达单细胞量级、附带损伤近μm量级，是高精度脑微创手术的理想选择，但是满足临床应用需求的高功率大脉冲能量6.45μm激光产生为目前该技术亟需解决的技术难点。本项目提出直接泵浦腔内光参量变频技术方案用于6.45μm固体激光源研究，与现有自由电子激光、腔外光参量变频激光研究手段相比，本技术方案可充分利用基频激光源腔内高能量密度、振荡过程多次非线性变频叠加的特点，有效提高变频效率及结构紧凑性。本项目拟进行该技术方案6.45μm激光产生基础问题研究，以突破光源研究的关键技术，为6.45μm激光医疗设备研发奠定基础。

脑瘤严重影响人类神经系统的功能及生命，其及时发现与清除极为重要，但手术过程中对重要功能区的神经中枢、血管、组织等的附带损伤将直接影响患者生命、或相关组织功能完整性。6.45 μm激光可作为激光刀对病变组织进行高精度切除的同时实现毗邻结构最小附带损伤，其切除精度可达单细胞量级、附带损伤近μm量级，是高精度脑微创手术的理想选择，但是满足临床应用需求的高功率大脉冲能量6.45 μm激光产生为目前该技术亟需解决的技术难点。本项目开展6.45 μm固体激光产生基础问题研究，攻克关键技术，研发脑微创手术所需6.45 μm固体激光源，为6.45 μm激光医疗设备研发奠定基础。主要研究内容包括：具有不同脉冲特性的高功率纳秒至微秒脉冲基频激光源研制、中红外非线性晶体光学性能表征与评估、以及光参量6.45 μm激光产生问题研究，获得单脉冲能量mJ级的6.45 μm激光输出，为该波段目前最高单脉冲能量。