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1.
Anisotropic optical feedback of single frequency intra-cavity He--Ne laser 总被引:1,自引:0,他引:1 下载免费PDF全文
This paper presents the anisotropic optical feedback of a single
frequency intra-cavity He--Ne laser. A novel phenomenon was
discovered that the laser output an elliptical polarized frequency
instead of the initial linear polarized one. Two intensities with a
phase difference were detected, both of which were modulated in the
form of cosine wave and a fringe shift corresponds to a λ/2
movement of the feedback mirror. The phase difference can be
continuously modulated by the wave plate in the external cavity.
Frequency stabilization was used to stabilize the laser frequency so
as to enlarge the measuring range and improve the measurement
precision. This anisotropic optical feedback system offers a
potential displacement measurement technology with the function of
subdivision of λ/2 and in-time direction judgment.
The three-mirror Fabry--Perot cavity model is used to present the
experimental results. Given the lack of need of lasing adjustment,
this full intra-cavity laser can significantly improve the
simplicity and stability of the optical feedback system. 相似文献
2.
实验利用双反馈半导体激光器获得了关联维数为3.8的高维混沌光.同时对比分析了双反馈与单反馈两种不同模式产生混沌的区别.结果表明:在反馈强度均为-26 dB时,双反馈产生混沌的关联维数高于单反馈产生混沌的关联维数2.6;双反馈可获得带宽为11 GHz的混沌光,为单反馈产生混沌带宽5.5 GHz的两倍.当双反馈的两个外腔长度不相等时,混沌的自相关曲线能很好的隐藏外腔长度信息,可提高混沌通信的保密性.
关键词:
双反馈
半导体激光器
混沌
带宽 相似文献
3.
腔调谐过程中同时对HeNe激光器进行光回馈,设定回馈镜驱动信号的周期远小于腔调谐信号的周期,此时便获得腔调谐过程中谐振腔中两垂直偏振光的回馈信号. 回馈的形式分为仅垂直光回馈、仅平行光回馈以及两光同时回馈三种情况. 当两光同时回馈时,两模式间的模竞争较弱,两光回馈曲线有一定的相位差,该相位差小于180°,两光总体波动幅度变化趋势相反. 当仅单偏振光回馈时,两模式间的模竞争较强,两光回馈曲线始终反相,而且两光波动幅度变化趋势相同,此时可以将两光强度信号相减以实现成倍提高回馈信号幅度,从而提高系统灵敏度. 尤其仅垂直光回馈时,两光各自光强波动幅值都较大,并且在较大的增益曲线范围内保持光强波动幅值无明显变化,该特性可用于提高回馈系统的抗干扰能力,减少因激光功率漂移而引起的错误计数.
关键词:
自混合干涉
光回馈
模竞争
位移测量 相似文献
4.
Optical feedback characteristics in a dual-frequency laser during laser cavity tuning 总被引:1,自引:0,他引:1 下载免费PDF全文
The optical feedback characteristics in a Zeeman-birefringence dual-frequency laser are studied during the laser cavity tuning in three different kinds of optical feedback conditions: (i) only // -light is fed back; (ii) only ⊥-light is fed back; (iii) both lights are fed back.A compact displacement sensor is designed using the experimental result that there is a nearly 90 degrees phase delay between the two lights' cosine optical feedback signals when both lights are fed back into the laser cavity.The priority order that the two lights' intensity curves appear can be used for direction discrimination. The resolution of the displacement sensor is at least 79 nm, and the sensor can discriminate the target's moving direction easily. 相似文献
5.
在一个双光反馈半导体激光混沌系统中,固定其中一个反馈腔镜(固定腔M1)的反馈延迟时间以及反馈强度,实验研究了另一个反馈腔镜(可变腔M2)的反馈延迟时间以及反馈强度对系统混沌输出的延时反馈特征的影响.研究结果表明:在可变腔M2与固定腔M1的反馈强度相等的条件下,改变M2的腔长,当其腔长约等于(但不能严格等于)M1的腔长或者腔长的一半时,系统将呈现较好地抑制延时反馈特征效果;当M
关键词:
半导体激光器
双光反馈
混沌输出
延时特征 相似文献
6.
Tsu-Chiang Yen Jer-Wei Chang Jenn-Ming Lin Rong-Jyh Chen 《Optics Communications》1998,150(1-6):158-162
This work examines the feasibility of using incoherent optical feedback to generate high-frequency optical signals in a semiconductor laser. At a roundtrip feedback distance of 30 cm, a signal appears at around 1 GHz while the laser output is kept in single longitudinal mode and single polarization. The proposed method does not use any external modulation or saturable absorber. Some of the signal's properties are discussed as well. 相似文献
7.
Intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level 下载免费PDF全文
This paper demonstrates the intensity modulation characters of orthogonally polarized HeNe lasers with different optical feedback level generated by the variable reflectivity of external reflector. The modulation depths of the orthogonally polarized frequencies are increased when the optical feedback level becomes strong. It also observes that the modulation amplitudes are different for different external cavity length. Based on the vectorial extension of Lamb's semi-classical theory, it finds that the calculations are consistent with the experimental results. 相似文献
8.
利用双光反馈垂直腔面发射半导体激光器(VCSELs) 两个正交偏振模式输出的两个混沌信号作为混沌载波, 构建了一个双信道的混沌保密通信系统, 并对该系统的通信性能进行了数值仿真研究.研究结果表明: 通过合理的选取反馈参量, 双光反馈VCSELs两个偏振模式输出的混沌信号能很好地隐藏外腔反馈延时特性; 双光反馈VCSEL两个偏振模式输出的混沌信号通过偏振保持注入到接收VCSEL中, 在强注入锁定条件下可以实现很好的混沌同步, 同步性能对频率失谐的容忍性随着注入强度的增加而加强; 在附加混沌调制加密方式下, 500 Mbit/s的信号在传输过程中能够得到很好的隐藏, 同时在接收端可以成功解调; 随着通信速率的增加, Q因子呈现下降的趋势, 但对于 6 Gbit/s的信息, Q因子仍大于6.
关键词:
垂直腔面发射激光器
双光反馈
双信道
混沌通信 相似文献
9.
Jiayin Qin Xingshi Zheng Xiao Huang Hui Dai Xizhang Luo Yikun Lin 《International Journal of Infrared and Millimeter Waves》1997,18(6):1285-1297
Based on the quantum mechanics theory of density matrix and the principle of multiple-beam interference, the tuning characteristics
of optically pumped NH3 FIR lasers were studied. A series of metallic mesh Fabry-Perot cavity lasers with sample tubes of 10cm, 20cm and 100cm in
length were constructed and operated successfully, and the FIR laser spectra of the NH3 cavity lasers pumped by a TEA-CO2 laser were measured.
Supported by the Natural Sciences Foundation of Guangdong Province, PRC 相似文献
10.
11.
为满足天文导航设备星敏感器内场高精度检测和标校的实际工程需要,设计了一种结构简单并且具有光反馈功能的新型高精度单星模拟器。选用发光二极管作为光源,采用先聚焦再准直的方法实现模拟星光的平行输出。星模拟器的光反馈系统可以在输出光强发生变化的时候自动调节星光光源的发光强度,从而使星模拟器的输出光强在相当长的时间段内保持稳定。星模拟器输出光束的平行度达到8,输出光束的均匀性达到80 %,在连续工作至少8 h的情况下输出光束的稳定性达到89 %。相对稳定的输出光强减少了星模拟器因为模拟的星等发生变化而产生的影响,提高了星敏感器检测和标定的精度。 相似文献
12.
13.
提出了一种基于双频激光回馈效应的位移测量系统,并在理论和实验两方面进行了研究.实验中对激光器输出功率变化进行了探测,同时对两正交偏振光的光强变化进行了探测.研究发现当被测物体移动时,激光器输出功率受到调制,物体每移动半个光波长时,回馈信号为调制深度相等的两峰,系统分辨率提高了一倍,达到四分之一光波长.当物体运动方向改变时,两正交偏振光的光强变化顺序也随之改变,可以实现物体位移方向的判断.理论分析及模拟结果与实验结果相符合.研究表明该位移传感系统具有结构简单、分辨率高、可判向、测量范围大、可工作于强回馈区等优点.
关键词:
激光回馈
位移传感
自混合干涉
双频激光器 相似文献
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15.
16.
Linlin LI 《Chinese Journal of Lasers》1992,1(2):111-116
In this paper the frequency modulation characteristics the semiconductor laserwith weak optical feedback are presented,considering both the frequency deviation and thespurious intensity modulation.The frequency modulation can be realized without spurious in-tensity modulation under proper feedback conditions.There is an optimal feedback intensity tomaximize the frequency deviation. 相似文献
17.
研究了在各向异性外腔下微片Nd:YAG激光器调频回馈特性.作为对比,首先给出了在各向同性外腔下调频回馈结果,激光器输出功率的半波条纹数正比于外、内腔长度之比.在回馈外腔中内置一个四分之一波片,激光偏振态发生规律性跳变,每个纵模带宽内的偏振跳变次数正比于外、内腔长之比,相同外腔长下,回馈条纹再次倍频.进行了基于法布里-珀罗腔等效模型的理论分析,结果和实验相符合.此现象在精密测量领域有潜在应用.
关键词:
光回馈
调频回馈
各向异性外腔
半波条纹数 相似文献
18.
本文在理论上研究了由于外部光反馈引起的半导体激光器的相位噪声.理论分析是通过引入一个反馈耦合率K和线性化速率方程,导出了半导体激光器相位噪声功率谱密度的表达式.这表明相位噪声功率谱密度随外腔长度而周期性地漂移,且功率谱密度的峰值随外部反馈耦合率而发生很大的变化. 相似文献
19.
Strong optical feedback in a birefringent dual frequency He--Ne laser with a
high reflectivity feedback mirror has been investigated for the first time.
The output characteristics of two orthogonally polarized modes are
demonstrated in two different optical feedback cases: one is for both modes
being fed back and the other is for only one of the modes being fed back.
Strong mode competition can be observed between the two modes with strong
optical feedback. And when one mode's intensity is near its maximum, the
other mode is nearly extinguished. When both modes are fed back into the
laser cavity, the mode competition is stronger than when only one mode is
fed back. The difference in initial intensity between the two orthogonally
polarized modes plays an important role in the mode competition, which has
been experimentally and theoretically demonstrated. 相似文献