Wavelength-Dependent Reflector for Optical Amplifier Parasitic Lasing
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Solution Overview
Problem
Tunable optical filters in existing light sources suffer from parasitic lasing, which limits their useful range to a narrow wavelength range due to the peak gain of the gain medium, leading to energy leakage and noise in optical systems requiring broader wavelength ranges.
Innovation Solution
Implementing wavelength-dependent reflectivity to inhibit reflection at the peak gain wavelengths while allowing reflection at other wavelengths, using surface coatings or materials that selectively reflect light based on wavelength, thereby suppressing parasitic lasing and enabling amplification across a broader range of wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a tunable optical filter is used to select a wavelength not at peak gain, then the desired wavelength can be obtained, but parasitic lasing occurs at the peak gain wavelength
Solution Approach 1:
The patent converts the harmful parasitic lasing at peak gain wavelength into a beneficial effect by using a wavelength-dependent reflector to selectively reflect only the peak gain wavelength back into the gain medium, where it is re-amplified and added to the desired wavelength signal, thereby eliminating the harmful energy loss while maintaining the desired wavelength selection capability
Solution Approach 2:
The wavelength-dependent reflector acts as an intermediary component between the tunable optical filter and the gain medium. It selectively intercepts the peak gain wavelength background light and redirects it back through the gain medium, preventing parasitic lasing while allowing the desired wavelength to pass through to the output
2Power
If high input power is used to amplify a selected frequency not at peak gain, then the desired output power is achieved, but the background light at peak gain surpasses the lasing threshold
Solution Approach 1:
The wavelength-dependent reflector is positioned to preemptively intercept the peak gain wavelength background light before it can accumulate sufficient power to reach the lasing threshold. By reflecting this light back through the gain medium early in the amplification process, the system prevents parasitic lasing from occurring, allowing high input power to be used for amplifying the desired wavelength without compromising lasing threshold control
3Reliability
If the tunable optical filter is kept within a narrow tuning range surrounding the peak gain, then parasitic lasing is avoided, but the useful range of the filter is limited
Solution Approach 1:
The patent changes the optical parameters of the system by introducing a wavelength-dependent reflector that selectively modifies the reflectivity at the peak gain wavelength. This parameter change allows the tunable optical filter to operate over a broad wavelength range while the reflector dynamically manages the peak gain wavelength light, preventing parasitic lasing across the entire extended tuning range
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the effective use of light at wavelengths not at the peak gain, increasing the usable range of tunable optical filters and preventing energy loss from parasitic lasing, thus enabling a single optical system to handle a broader range of wavelengths without energy leakage or noise.
Implementation Method 1
a reflector in optical communication with the optical amplifier, in which the reflector inhibits reflection of light at the peak gain and reflects light at wavelengths not at the peak gain
Implementation Method 2
The gain medium is a material that increases the power of light by stimulated emission when supplied with energy
Implementation Method 3
Input light resonates between the mirrors while being re-amplified by the gain medium until the lasing threshold is surpassed and laser light is produced
Data Source
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AI summary
The invention relates to optical system including light sources that amplify light using a gain medium. Systems and method of the invention are provided for amplifying light while inhibiting reflections at a peak gain of the gain medium, thereby suppressing parasitic lasing. This allows a system to use a broad range of wavelengths without parasitic lasing, thereby increasing the useable range of a tunable optical filter. In this manner, light at wavelengths not at a peak gain can be used effectively, and the gain medium of an optical amplifier does not limit use of a system to a narrow range of wavelengths associated with a peak gain of the gain medium. A single optical system according to the invention can thus be used for applications that require a broad range of wavelengths.