Related Experiment Video
Updated: Dec 6, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Stepped frequency comb generation based on electro-optic phase-code mode-locking for moderate-speed circular-ranging
Tae Shik Kim1,2, Benjamin J Vakoc1,2
1Harvard Medical School, Boston, Massachusetts 02115, USA.
Abstract:
Circular-ranging (CR) optical coherence tomography (OCT) uses frequency comb sources to improve long-range imaging. While the initial development of CR-OCT focused on extremely high-speed imaging (i.e., operation at A-line rates of several to tens of MHz), there are many applications and imaging strategies for which more moderate speeds are preferred. However, we lack suitable frequency comb sources to enable moderate speed CR-OCT imaging. Here, we describe a novel phase-code mode-locking (PCML) laser architecture that can be operated from the kilohertz to megahertz range, while also offering novel features such as dynamic re-configurability and simplified linear-in-time frequency stepping. We demonstrate a prototype CR-OCT system with a PCML laser and present imaging results at A-line rates from 176 kHz to 3.52 MHz with coherence-length limited imaging depths as high as 170 mm.
Related Concept Videos
Phase Contrast and Differential Interference Contrast Microscopy
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
Propagation Speed of Electromagnetic Waves
Imaging Biological Samples with Optical Microscopy
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
Time and frequency -Domain Interpretation of Phase-lag Control
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

