Wavelength stabilization for broadband light sources
AssigneeEM4, Inc.
InventorsMikhail Kaluzhny, Alex Rosiewicz
Life of this patent
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Abstract
A broadband light source, such as a light-emitting diode (LED), such as a superluminescent light-emitting diode (SLED), has its mean wavelength stabilized by using a filter to pass a characteristic of the output of the source, detecting the filtered output, and adjusting a parameter affecting the wavelength of the source, such as drive current or temperature. A Gaussian or near-Gaussian filter can be used to obtain an intensity detection, or two narrowband filters can be used where one filter passes a wavelength greater, and one passes a wavelength less, than the desired mean wavelength.
Claims23
An apparatus comprising:
- a broadband light source for emitting light with a mean wavelength;
- a filter with a generally Gaussian spectral distribution for receiving light from the source for filtering the light to provide filtered light;
- a first detector for detecting the filtered light and for providing a signal indicative of a parameter of the filtered light;
- and
- a control system responsive to the signal from the detector for controlling the mean wavelength of the light emitted from the source if the mean wavelength deviates from a desired value.
An apparatus comprising:
- a broadband light source for emitting light with a mean wavelength;
- a first narrowband filter for receiving light from the source and for passing light with a wavelength greater than the mean wavelength;
- a second filter receiving light from the source and for passing light with a wavelength less than the mean wavelength;
- a first detector for detecting light from the first filter and for providing a first signal;
- a second detector for detecting light from the second filter and for providing a second signal;
- and
- a control system responsive to the first and second signals and for controlling the mean wavelength of the light emitted from the source if the mean wavelength deviates from a desired value.
Dependencies are inferred from the claim text.