为了保持电光调制器(EOM)输入光偏振方向始终与其内部可传播模式偏振方向一致,使EOM获得良好的调制效果,提出了一种基于比例-积分-微分(PID)算法的EOM自适应偏振控制方法,理论分析并实验验证了该方法的可行性。实验结果表明,基于该方法...为了保持电光调制器(EOM)输入光偏振方向始终与其内部可传播模式偏振方向一致,使EOM获得良好的调制效果,提出了一种基于比例-积分-微分(PID)算法的EOM自适应偏振控制方法,理论分析并实验验证了该方法的可行性。实验结果表明,基于该方法设计的控制系统不仅能实时监测EOM输出光功率,而且能保持其输出光功率最大;与激光器和EOM输入端直接用保偏光纤连接时相比,PID偏振控制下EOM输出平均功率提高了3.08 d B,PD输出电压标准差由0.121 4降至1.237 5×10-4,稳定控制状态下偏振态矫正时间在ms量级。展开更多
Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice C...Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice CT scanner. For each subject, one axial image at the central level of the eyeball, one coronal image about 1 cm behind globe, and two oblique sagittal images respectively along the left and right optic nerve were used for measurements of the thickness and width of EOMs. The statistic significance of measurement value between male and female and between left and right eyes was evaluated. Results There were no significant differences in the thickness and width of superior muscle group, lateral rectus, medial rectus, lateral rectus, superior oblique, inferior oblique and the thickness of levator palpebrae superioris between the left and right eyes as well as between male and female groups (all P>0.05). The thickness of superior muscle group and inferior rectus had not significant difference (2.9±0.7 vs. 3.3±0.8 mm, P=0.162), while the thickness of medial rectus was significantly higher than that of lateral rectus (3.1±0.5 vs. 2.2±0.6 mm, P=0.000). Conclusions The CT measurement of extraocular musculature is simple and time-saving and can be applied in the clinical work. The normative data obtained may be useful in determining pathologic enlargement of the EOMs in both thyroid-associated orbitopathy patients and other various orbital conditions.展开更多
文摘为了保持电光调制器(EOM)输入光偏振方向始终与其内部可传播模式偏振方向一致,使EOM获得良好的调制效果,提出了一种基于比例-积分-微分(PID)算法的EOM自适应偏振控制方法,理论分析并实验验证了该方法的可行性。实验结果表明,基于该方法设计的控制系统不仅能实时监测EOM输出光功率,而且能保持其输出光功率最大;与激光器和EOM输入端直接用保偏光纤连接时相比,PID偏振控制下EOM输出平均功率提高了3.08 d B,PD输出电压标准差由0.121 4降至1.237 5×10-4,稳定控制状态下偏振态矫正时间在ms量级。
文摘Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice CT scanner. For each subject, one axial image at the central level of the eyeball, one coronal image about 1 cm behind globe, and two oblique sagittal images respectively along the left and right optic nerve were used for measurements of the thickness and width of EOMs. The statistic significance of measurement value between male and female and between left and right eyes was evaluated. Results There were no significant differences in the thickness and width of superior muscle group, lateral rectus, medial rectus, lateral rectus, superior oblique, inferior oblique and the thickness of levator palpebrae superioris between the left and right eyes as well as between male and female groups (all P>0.05). The thickness of superior muscle group and inferior rectus had not significant difference (2.9±0.7 vs. 3.3±0.8 mm, P=0.162), while the thickness of medial rectus was significantly higher than that of lateral rectus (3.1±0.5 vs. 2.2±0.6 mm, P=0.000). Conclusions The CT measurement of extraocular musculature is simple and time-saving and can be applied in the clinical work. The normative data obtained may be useful in determining pathologic enlargement of the EOMs in both thyroid-associated orbitopathy patients and other various orbital conditions.
