S. Makita

Birefringence imaging of human skin by polarization-sensitive spectral interferometric optical coherence tomography

We have developed a spectral interferometric optical coherence tomography (OCT) system with polarization sensitivity that is able to measure a two-dimensional tomographic image by means of one-dimensional mechanical scanning. Our system, which has an axial resolution of 32 mum , calculates the distribution of each element of the Müller matrix of a measured object from 16 OCT images. The OCT system successfully reveals the birefringent nature of human skin tissue.

Polarization sensitive Fourier domain optical coherence tomography with continuous polarization modulation

Polarization sensitive Fourier domain optical coherence tomography (PS-FD-OCT) using fiber components with continuous polarization modulation is demonstrated. The incident polarized light is modulated by electro-optic modulator (EO modulator) synchronized with lateral B-scanning. By the incident polarization modulation and the polarization sensitive spectrometer, the depth-resolved Jones matrix image of biological sample can be measured. This method uses both polarization modulation method and Fourier transform method. In this paper, the algorithm is described and the phase retardation image of chicken breast muscle is measured.

Spectral interferometric optical coherence tomography with nonlinear β-barium borate time gating

A high-speed, all optical coherence tomography system was designed and constructed. This tomography system employs spectral interferometry and optical Fourier transformation to reduce the number of mechanical scanning dimensions required for multidimensional profilometry. The system also employs a time gate comprising a beta -barium borate crystal driven by a femtosecond laser pulse to improve measurement time. This system has 43-mum depth resolution and 150-fs temporal resolution and is capable of taking 1000 cross-sectional image frames per second.

Three-dimensional optical coherence tomography of proliferative diabetic retinopathy

ABSTRACT Fourier-domain optical coherence tomography (OCT) was used to image the three-dimensional (3D) structures of the proliferative membrane in proliferative diabetic retinopathy. The case of a 51-year-old man with retinal detachment of the macula in his left eye is reported. The proliferative membrane covered the entire macular area. In the OCT image, the 3D structure of the proliferative membrane could be clearly visualised. The OCT image showed the presence of multiple adhesions between the retina and the proliferative membrane and separation of the proliferative membrane. The patient underwent three-port vitrectomy, and the extent and locations of the adhesions corresponded well with the findings during vitrectomy. Three-dimensional OCT is an effective tool for understanding the 3D structure of the proliferative membrane in diabetic retinopathy and is useful for training and planning of the surgical procedures in vitrectomy. To view the full report and accompanying video please go to: http://bjo.bmj.com/cgi/content/full/92/5/713/DC1 All videos from the BJO video report collection are available from: http://bjo.bmj.com/video/collection.dtl

Investigation of Retinal Micro-Structure by Adaptive Optics Scanning Laser Ophthalmoscope with 1-Micrometer Wavelength Probe

Adaptive optics scanning laser ophthalmoscope with 1-micrometer band probe is presented. The residual wavefront error was less than 0.02 with in vivo human eye. Photoreceptor cones are visualized at the eccentricity up to 10 degrees.

Three-dimensional evaluation of in vivo human skin by spectral domain and swept source optical coherence tomography

After segmentation of the epidermis from three-dimensional coherence tomography volume, a depth-oriented algorithm provides a segmentation of the infundibulum. In this process, the epidermal thickness, the population and the occupation ratio of the infundibula are provided.

Standard and Line-Field Fourier Domain Optical Coherence Tomography

Standard Fourier domain optical coherence tomography (FD-OCT) and line-field Fourier domain optical coherence tomography (LF-FDOCT) are described. The standard FD-OCT has the measurement speed of 36 frames/sec and one frame consisting 500 A-scans. The LF-FDOCT is an improved version of FD-OCT and determines a cross section of a sample without any mechanical scanning. The LF-FDOCT has the measurement speed of 30 frames/sec, which is corresponding to 480 KH/ A-scan. A galvano-meter is introduced into the LF-FDOCT and it enables three-dimensional OCT measurement with only one-dimensional mechanical scanning

In vivo human retinal imaging using high-speed Doppler Fourier-domain optical coherence tomography

We develop high-speed Fourier-domain optical coherence tomography. A-scan rate is 18700 Hz and system sensitivity is 90.3 dB with –50.3 dB reflector. In vivo human retinal structure and blood flow imaging are demonstrated.

Dermatological Investigation by Three-Dimensional Line-Field Fourier Domain Optical Coherence Tomography

Three-dimensional optical coherence tomography using only one-dimensional mechanical scanning is demonstrated. This system uses the principle of Fourier domain optical coherence tomography for depth resolution, one-dimensional imaging for lateral vertical resolution, and mechanical scanning by a galvanometer for lateral horizontal resolution. An in vivo human fingerpad is investigated three-dimensionally. The acquisition time for a single cross section is 1 ms and that for a single volume is 10 s, and the system sensitivity is 75.6 dB.

Laterally super-resolving optical coherence tomography by complex numerical method

A method of lateral superresolution for Fourier domain optical coherence tomography is presented. This method consists of intentional defocus and its numerical compensation using a spatial frequency-phase filter. Theoretical consideration and experimental demonstration are described.