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 lin...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.展开更多
A novel approach is proposed towards the design of fiber Bragg gratings with multi-channel right-angled triangular spectrum.Firstly,a single-channel grating is synthesized utilizing an adaptive quantum particle swarm ...A novel approach is proposed towards the design of fiber Bragg gratings with multi-channel right-angled triangular spectrum.Firstly,a single-channel grating is synthesized utilizing an adaptive quantum particle swarm optimization with the piecewise constant mutated factor.Meanwhile,the reflectivity spectrum with good linear edge for a short grating is obtained.Then,for its merits of easy fabrication,the superposition method is adopted to design multi-channel gratings with initial spectral distortion.Finally,this distortion is optimized by the method in the first step.It is shown that the design outcomes still retain the features of easy fabrication and short length.Such gratings would be useful as wavelength-interrogation devices with multiple physical parameters in optical sensor systems.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 60437010)
文摘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.
基金Supported by National Science Foundation of China under Grant Nos 60977034,61107036,11004043,11274083in part by China Postdoctoral Science Foundation under Grant Nos 20110491092,2012T50354.
文摘A novel approach is proposed towards the design of fiber Bragg gratings with multi-channel right-angled triangular spectrum.Firstly,a single-channel grating is synthesized utilizing an adaptive quantum particle swarm optimization with the piecewise constant mutated factor.Meanwhile,the reflectivity spectrum with good linear edge for a short grating is obtained.Then,for its merits of easy fabrication,the superposition method is adopted to design multi-channel gratings with initial spectral distortion.Finally,this distortion is optimized by the method in the first step.It is shown that the design outcomes still retain the features of easy fabrication and short length.Such gratings would be useful as wavelength-interrogation devices with multiple physical parameters in optical sensor systems.
