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Vector modulation instability in gas-filled multi-pass cells
Optics Letters
|July 31, 2026
Summary
Vector modulation instability (VMI) limits nonlinear pulse compression in multi-pass cells (MPCs) at high B-integrals. Circularly polarized input pulses suppress VMI, enabling greater compression factors.
Area of Science:
- Nonlinear optics
- Laser physics
- Optical engineering
Background:
- Multi-pass cells (MPCs) enable significant nonlinear pulse compression.
- Performance is limited by secondary nonlinear effects at high B-integrals, causing spectral issues.
- Vector modulation instability (VMI) is identified as a key limiting factor.
Purpose of the Study:
- To experimentally observe and characterize VMI in gas-filled MPCs.
- To identify VMI as a primary limitation in high B-integral regimes.
- To investigate mitigation strategies for enhanced pulse compression.
Main Methods:
- Experimental setup utilizing gas-filled MPCs.
- Operation at B-integrals exceeding 30 radians.
- Polarization analysis of generated spectral features.
- Comparative studies with linear and circular input polarizations.
- Numerical simulations for validation.
Main Results:
- Experimental observation of VMI in gas-filled MPCs.
- VMI signal is orthogonally polarized to the input beam.
- VMI gain scales with accumulated B-integral, not solely gas density or peak power.
- Circularly polarized input pulses effectively suppress VMI.
- Simulations confirm VMI suppression and enhanced compression.
Conclusions:
- VMI is a primary limiting mechanism in gas-filled MPCs at high B-integrals.
- Circular polarization is a viable strategy to mitigate VMI.
- Combined with dispersion management, this enables single-stage compression factors exceeding 40.
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