Arbitrary Optical Pulse Generation via Dual-Modulator Segmentation
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Solution Overview
Problem
Existing optical pulse-generation methods cannot produce an optical pulse train with an arbitrary pattern, limiting their flexibility and application in various optical communication and spectroscopy techniques.
Innovation Solution
An optical pulse-generator system comprising a first optical modulator, a second optical modulator with a synchronized signal pattern, and a dispersion compensator, along with an optical pulse compressor and phase adjuster, allows for the generation of optical pulses with arbitrary patterns by modulating input light and compensating chirp, using lithium niobate modulators and optimizing the placement of dispersion compensators and intensity modulators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light is modulated to produce an optical frequency comb using a single modulator, then the repetition frequency can be changed, but it is not possible to generate an optical pulse train with an arbitrary pattern
Solution Approach 1:
The patent divides the modulation function into two separate optical modulators: a first modulator that generates the optical frequency comb with adjustable repetition frequency, and a second modulator that selects specific pulses to create arbitrary patterns. This segmentation allows each modulator to perform a specialized function, achieving pattern flexibility while maintaining manageable system complexity
Solution Approach 2:
The patent employs lithium niobate modulators that can operate in multiple modes - they can function as intensity modulators, phase modulators, or frequency modulators depending on the applied electrical signal. This multi-functionality allows the same hardware to achieve various pulse patterns and frequency configurations without requiring separate specialized devices
2Manufacturing precision
If dispersion compensation is applied after pulse selection, then the chirp of selected pulses is compensated, but the timing synchronization between modulators becomes more critical
Solution Approach 1:
The patent applies dispersion compensation after the pulse selection process rather than before. By compensating the chirp of already-selected pulses, the system ensures high pulse quality for the final output. The phase adjuster performs preliminary timing alignment of the electrical signals driving both modulators, ensuring that pulse selection occurs at the correct moments in the optical frequency comb cycle
Solution Approach 2:
The patent includes a phase adjuster that can dynamically control the relative timing between the electrical signals applied to the first and second modulators. This feedback mechanism allows precise synchronization to be maintained and adjusted, ensuring that the pulse selection process occurs at the correct phase relationship between the two modulators while keeping the system adaptable to different operating conditions
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
Enables the generation of optical pulse trains with arbitrary patterns and adjustable repetition frequencies, improving the flexibility and quality of optical pulses for advanced applications in terahertz time-domain spectroscopy and other fields.
Implementation Method 1
a first optical modulator configured to modulate input light using a first modulation signal to generate optical pulses
Implementation Method 2
a second optical modulator configured to perform a modulation operation using a second modulation signal synchronizing with the first modulation signal and having a signal pattern that is set to output only specific part of the optical pulses
Implementation Method 3
a dispersion compensator configured to compensate a chirp of the optical pulse output from the first optical modulator
Implementation Method 4
an optical pulse compressor configured to perform a soliton compression to an optical pulse from a follower one of the second optical modulator and the dispersion compensator along the optical transmission direction
Data Source
AI summary
Provided is an optical pulse-generator and an optical pulse-generating method which are capable of generating an optical pulse train with an arbitrary pattern. An optical pulse-generator 1 includes a first optical modulator 21 configured to modulate input light using a first modulation signal SIG1 to generate optical pulses, a second optical modulator 41 configured to perform a modulation operation using a second modulation signal SIG2 synchronizing with the first modulation signal SIG1 and having a signal pattern that is set to output only specific part of the optical pulses, and a dispersion compensator 30 configured to compensate a chirp of the optical pulse output from the first optical modulator 21.