Dispersion in a grating-based optical delay line for optical coherence tomography

Niblack, Walter K.; Schenk, John O.; Liu, Bin; Brezinski, Mark E.

doi:10.1364/ao.42.004115

Cited by 31 publications

(17 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The grating and the swaying mirror are placed on the front and back focus planes, respectively, which can optimize dispersion match. 30,31 The sample arm is equipped with a handheld detector that scans laterally. It consists of a fiber collimator, a scanning mirror and an achromatic lens.…”

Section: Methodsmentioning

confidence: 99%

Imaging port wine stains by fiber optical coherence tomography

Zhao

Xue

et al. 2010

J. Biomed. Opt.

View full text Add to dashboard Cite

Abstract. We develop a fiber optical coherence tomography ͑OCT͒ system in the clinical utility of imaging port wine stains ͑PWS͒. We use our OCT system on 41 patients with PWS to document the difference between PWS skin and contralateral normal skin. The system, which operates at 4 frames/ s with axial and transverse resolutions of 10 and 9 m, respectively, in the skin tissue, can clearly distinguish the dilated dermal blood vessels from normal tissue. We present OCT images of patients with PWS and normal human skin. We obtain the structural parameters, including epidermal thickness and diameter and depth of dilated blood vessels. We demonstrate that OCT may be a useful tool for the noninvasive imaging of PWS. It may help determine the photosensitizer dose and laser parameters in photodynamic therapy for treating port wine stains.

show abstract

Section: Methodsmentioning

confidence: 99%

Imaging port wine stains by fiber optical coherence tomography

Zhao

Xue

et al. 2010

J. Biomed. Opt.

View full text Add to dashboard Cite

show abstract

“…At each gap distance, we perform displacement of the mirror in the reference arm from 0 to 3 cm at increments of 0.5 cm. A 1 cm displacement corresponds to a theoretical classical point spread function (PSF) of 66.7 um while 2 cm displacement would be 133.4 µm [40,42]. As the mirror is displaced, each peak in the A scan interferogram widens until chirping occurs.…”

Section: Methodsmentioning

confidence: 99%

Nonlocal quantum macroscopic superposition in a high-thermal low-purity state

Brezinski

Liu

2008

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

Quantum state exchange between light and matter is an important ingredient for future quantum information networks as well as other applications. Photons are the fastest and simplest carriers of information for transmission but in general, it is difficult to localize and store photons, so usually one prefers choosing matter as quantum memory elements. Macroscopic superposition and nonlocal quantum interactions have received considerable interest for this purpose over recent years in fields ranging from quantum computers to cryptography, in addition to providing major insights into physical laws. However, these experiments are generally performed either with equipment or under conditions that are unrealistic for practical applications. Ideally, the two can be combined using conventional equipment and conditions to generate a “quantum teleportation”-like state, particularly with a very small amount of purity existing in an overall highly mixed thermal state (relatively low decoherence at high temperatures). In this study we used an experimental design to demonstrate these principles. We performed optical coherence tomography (OCT) using a thermal source at room temperatures of a specifically designed target in the sample arm. Here, position uncertainty (i.e., dispersion) was induced in the reference arm. In the sample arm (target) we placed two glass plates separated by a different medium while altering position uncertainty in the reference arm. This resulted in a chirped signal between the glass plate reflective surfaces in the combined interferogram. The chirping frequency, as measured by the fast Fourier transform (FFT), varies with the medium between the plates, which is a nonclassical phenomenon. These results are statistically significant and occur from a superposition between the glass surface and the medium with increasing position uncertainty, a true quantum-mechanical phenomenon produced by photon pressure from two-photon interference. The differences in chirping frequency with medium disappears when second-order correlations are removed by dual balanced detection, confirming the proposed mechanism. We demonstrated that increasing position uncertainty at one site leads to position uncertainty (quantum position probability amplitude) nonlocally via second-order correlations (two-photon probability amplitude) from a low coherence thermal source (low purity, high local entropy). The implications, first, are that the phenomenon cannot be explained through classical mechanisms but can be explained within the context of quantum mechanics, particularly relevant to the second-order correlations where controversy exists. More specifically, we provide the theoretical framework that these results indicate a nonlocal macroscopic superposition is occurring through a two-photon probability amplitude-induced increase in the target position probability amplitude uncertainty. In addition, as the experiments were performed with a classical source at room temperature, it supports both the quantum-mechanical properties of s...

show abstract

“…The SiC waveguides fabricated here considering only the second order term in the refractive index function τ crit =92 fs expanding the PSF by 325 μm and thus deteriorating the system resolution. A double-pass grating system based chromatic dispersion compensation scheme [10] was then used to correct the material dispersion (Fig .2) By changing a geometrical parameter in the setup, any dispersion value and sign can be generated. A group delay dispersion of opposite sign to the one stemming from the thermo-optic delay line can be introduced.…”

Section: ) Chromatic Dispersionmentioning

confidence: 99%

Demonstration of PECVD SiC thermal delay lines for optical coherence tomography in the visible

2010

View full text Add to dashboard Cite

Optical Coherence Tomography (OCT) has found applications in many fields of medicine and has a large potential for the optical biopsy of tumors. One of the technological challenges impairing faster adoption of OCT is the relative complexity of the optical instrumentation required, which translates into expensive and bulky setups. In this paper we report an implementation of Time-Domain Optical Coherence Tomography based on Plasma Enhanced Chemical Vapor Deposition (PECVD) Silicon Carbide (SiC). The devices, with a footprint of 0.3 cm 2 , are fabricated using rib waveguides defined in a SiC layer. While most of the components needed are known when using this material [1], a fast delay line with sufficient scanning range is a specific requirement of Time Domain (TD)-OCT. In the system reported here this is obtained making use of the thermo-optical effect. Though the current implementation still requires external sources and detectors to be coupled to the planar waveguide circuit, future work will include three-dimensional integration of these components onto the substrate to achieve a fully autonomous and compact OCT chip. With the potential to include the read-out and driving electronics on the same die, the reported approach can yield extremely compact and low-cost TD-OCT systems in the visible, enabling a broad range of new applications, including OCT devices for harsh environment.

show abstract

Dispersion in a grating-based optical delay line for optical coherence tomography

Cited by 31 publications

References 10 publications

Imaging port wine stains by fiber optical coherence tomography

Imaging port wine stains by fiber optical coherence tomography

Nonlocal quantum macroscopic superposition in a high-thermal low-purity state

Demonstration of PECVD SiC thermal delay lines for optical coherence tomography in the visible

Contact Info

Product

Resources

About