半导体激光鼓膜造孔术的光学系统设计

Design of optical system for diode laser myringotomy

设计并研制了一套可在视频监控和红光指示下实施半导体激光鼓膜造孔术的光学系统。首先,利用光束整形和波长合束技术将半导体激光单管出射的650nm激光和半导体激光列阵出射的810nm激光耦合到芯径为200μm,数值孔径为0.22的光纤中;然后,利用消色差透镜准直光纤出射的双波长激光,再利用另一个消色差透镜将光束聚焦到耳鼓膜上,该聚焦镜可通过机械部件沿光轴方向移动,从而调节鼓膜上光斑的大小;成像部分则直接使用商用视频耳镜;热反射镜用于使激光和成像光同轴。手术时,根据显示器上的红色指示光斑确定造孔位置。测量结果显示:该系统出光孔处的激光功率在0～13.3W间连续可调,造孔直径在1～3mm内连续可调。使用本系统可缩短手术时间,减少并发症;儿童患者手术时无需全身麻醉。另外,该系统还具有整机体积小、重量轻、电光转换效率高等优点。

An optical system to perform the semiconductor laser myringotomy with the help of a video display and a pilot laser was designed and manufactured.First,the 650 nm laser output from a single emitter and the 810 nm laser emitted from a laser diode array were coupled into a fiber with a core diameter of 200 μm and a numerical aperture of 0.22 by using beam shaping and wavelength beam combination technologies.Then,an achromatic lens was used to collimate the dual wavelength laser output from the optical fiber and the other achromatic lens which could move along principal axis and consequently change the spot size was used to focus the dual wavelength laser to the eardrum.Meanwhile,laser and imaging lights were coupled as coaxial by using a hot mirror and the imaging components from markets.Moreover,the location of myringotomy could be piloted by red light on a computer monitor.According to the results of measurement,the laser power output from the system can be continuously adjusted from 0 to 13.3 W,and the spot size can also be adjusted between 1-3 mm.The system can decrease the operation time and the possibility of surgery side effect;moreover,the myringotomy for children needs not any anasthesia.In addition,the system has the virtues of low volume,light weighted and high wall-plug efficiencies compared with other candidates.