Quasi-Phase Matching Grating Designer

Design programmable χ⁽²⁾ gratings for optimal nonlinear conversion

Grating Design Parameters

1550 nm
20 μm
50%
50
0 μm/mm

χ⁽²⁾ Spatial Distribution

Phase Matching Bandwidth

Total Length
1.0 mm
PM Bandwidth
2.5 nm
Peak Efficiency
95%
Pixel Count
133
Sidelobe Level
-13 dB

2D Programmable Pattern (Light Intensity Map)

Fourier Components

Grating Parameters

Fundamental k-vector 0.314 /μm
Effective χ⁽²⁾ 0.30 pm/V
1st Order Coefficient 0.637
Walk-off Length 2.5 mm
Temperature Sensitivity 0.05 nm/°C

QPM Theory

Quasi-Phase Matching

Periodic modulation of χ⁽²⁾ provides momentum to compensate phase mismatch:

k - 2kω - Kg = 0

where Kg = 2π/Λ is the grating vector

Effective Nonlinearity

The effective χ⁽²⁾ for first-order QPM:

χ(2)eff = (2/π) χ(2) sin(πD)

Maximum at 50% duty cycle (D = 0.5)