Methods, systems, and devices for timing control in electromagnetic radiation sources
AssigneeLightLab Imaging, Inc.
InventorDesmond Adler
Life of this patent
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Abstract
In one embodiment, the invention relates to systems, methods and devices for improving the operation of an electromagnetic radiation source or component thereof. In one embodiment, the source is a laser source. A Fourier domain mode locked laser can be used in various embodiments. The sources described herein can be used in an optical coherence tomography (OCT) system such as a frequency domain OCT system. In one embodiment, laser coherence length is increased by compensating for dispersion. A frequency shifter can also be used in one embodiment to compensate for a tunable filter induced Doppler shift.
Claims21
A method of compensating for a Doppler shift induced by a tunable filter in a laser comprising
- determining a Doppler shift frequency induced by at least one element disposed inside the laser;
- sweeping a tunable filter such that a plurality of Doppler shifted wavelengths are generated in a laser cavity;
- applying an optical frequency shift that is equal in magnitude and opposite in direction to the Doppler shift frequency using an optical frequency shifter in optical communication with the tunable filter;
- and
- transmitting a plurality of Doppler shift compensated wavelengths outside of the laser cavity.
A laser having a wavelength range and a coherence length comprising:
- a laser cavity;
- an optical delay line;
- a gain element in optical communication with the optical delay line;
- a first optical coupler in optical communication with the gain element;
- a dispersion compensation module in optical communication with the first optical coupler;
- a bi-directionally tunable filter in optical communication with the dispersion compensation module, and
- a frequency shifter in optical communication with the dispersion compensation module,
- wherein the gain element, the bi-directionally tunable filter, and the dispersion compensation module are disposed in the laser cavity.
A dispersion compensation module comprising:
- a first chirped fiber Bragg grating having a first input;
- a second chirped fiber Bragg grating having a second input;
- and
- a four port circulator, wherein a first port is an input port, a second port is an output port, a third port is in optical communication with the first input, and a fourth port is in optical communication with the second input.
Dependencies are inferred from the claim text.