The birefringence optical feedback with a folded cavity in HeNe laser is investigated.A theory model based on the equivalent cavity of the Fabry–Perot interferometer is presented.The phase difference between the two ...The birefringence optical feedback with a folded cavity in HeNe laser is investigated.A theory model based on the equivalent cavity of the Fabry–Perot interferometer is presented.The phase difference between the two intensities in birefringence feedback is twice the retardation of the wave plate.The phase difference is invariable when the length of the feedback cavity changes.With the adoption of a cube corner prism(CCP)to form a folded cavity,the fringe frequency is doubled,and the resolution of the displacement sensor based on birefringence optical feedback with a folded cavity is improved.A resistance chain of 5-fold subdivision and 4-fold logic subdivision is used as further subdivision.The resolution ofλ/80 is obtained eventually;for 632.8 nm HeNe laser it is 7.91 nm.The displacement sensor based on birefringence optical feedback with a folded cavity is simple and of high resolution,large measurement range,low cost,and is of great application potential in industry.展开更多
基金Supported by the National Natural Science Foundation of Beijing under Grant No 3091002.
文摘The birefringence optical feedback with a folded cavity in HeNe laser is investigated.A theory model based on the equivalent cavity of the Fabry–Perot interferometer is presented.The phase difference between the two intensities in birefringence feedback is twice the retardation of the wave plate.The phase difference is invariable when the length of the feedback cavity changes.With the adoption of a cube corner prism(CCP)to form a folded cavity,the fringe frequency is doubled,and the resolution of the displacement sensor based on birefringence optical feedback with a folded cavity is improved.A resistance chain of 5-fold subdivision and 4-fold logic subdivision is used as further subdivision.The resolution ofλ/80 is obtained eventually;for 632.8 nm HeNe laser it is 7.91 nm.The displacement sensor based on birefringence optical feedback with a folded cavity is simple and of high resolution,large measurement range,low cost,and is of great application potential in industry.