Bingjie Huang

Full-range parallel Fourier-domain optical coherence tomography using a spatial carrier frequency

We propose a method of parallel full-range Fourier-domain optical coherence tomography (FDOCT) that is capable of acquiring an artifacts-free B-scan image by a single shot of a two-dimensional (2D) CCD camera. This method is based on a spatial carrier technique in which a spatial carrier-frequency is instantaneously introduced into the 2D spectral interferogram registered in parallel FDOCT by using a grating-generated line-reference beam. The spatial-carrier-contained 2D spectral interferogram is processed through Fourier transformation to obtain a complex 2D spectral interferogram, from which a full-range B-scan tomogram is reconstructed. The principle of our method is confirmed by imaging a tropical fish eyes anterior chamber and a shrimp telson in vivo. The suppression ratio of the complex conjugate artifact can reach 36 dB.

Single-shot parallel full range complex Fourier-domain optical coherence tomography

We present a method of parallel full range complex Fourier-domain optical coherence tomography (FDOCT) that is capable of acquiring an artifacts-free two-dimensional (2-D) cross-sectional image, i.e. a full range B-scan tomogram, by a single shot of 2-D CCD camera. This method is based on a spatial carrier technique, in which the spatial carrier-frequency is instantaneously introduced into the 2-D spectral interferogram registered in parallel FDOCT by using a grating-generated reference beam. The spatial-carrier-contained 2-D spectral interferogram is processed through Fourier transformation to obtain a complex 2-D spectral interferogram. From the 2-D complex spectral interferomgram, a full range B-scan tomogram is reconstructed. The principle of our method is confirmed by imaging an onion sample.

Method for eliminating the influence of light intensity modulation in sinusoidal phase modulating laser diode interferometer

In a conventional sinusoidal phase-modulating laser-diode (SPM-LD) interferometer, the wavelength of LD is sinusoidally modulated by varying its injection current. However, the intensity modulation is associated with wavelength modulation, which affects the measurement accuracy. We propose here a method to eliminate the effect of intensity modulation by choosing appropriate modulation depth for sinusoidal phase modulation in a SPM-LD interferometer. The method is verified by computer simulation and experiment for real-time displacement measurement. The measurement accuracy has been improved and the measurement repeatability is less than 1 nm.

Parameter optimization of optically excited microresonator by a semiconductor laser subject to optical feedback

A novel approach of optically exciting and detecting the vibration of a microresonator by a sinusoidally driven semiconductor laser subject to optical feedback is proposed. A theoretical model for the approach is established, and the working parameters are optimized. In our experiments, an Al-coated microcantilever is designed with optimized working parameters, and the microcantilever is optically excited by a sinusoidally driven semiconductor laser. We have demonstrated that there exist periodic dips of the optical power of semiconductor laser, which is caused by the resonant vibration of microcantilever. The optical power of semiconductor laser is also analyzed theoretically by using L-K equations. The experimental result is consistent with the result of theoretical analysis.