new example notebooks

[tylerflex]

These are some notebooks I've been working on.

We probably dont want to merge as is, but would be potentially interesting to pick up by any AEs.

I will continue to add to this branch:

1. Grating Coupler Inverse Design

Inverse Design of Grating Coupler

• Uses Tidy3D autograd for adjoint-based optimization
• Optimizes grating structure for fiber-to-chip coupling
• Topology optimization with filter+projection for fabricability

2. LED light extraction

LED Light Extraction Optimization

• Designs surface structures to improve light extraction from LEDs
• Overcomes total internal reflection limit
• Uses inverse design to maximize extraction efficiency

3. Ray Tracing

Multi-Scale Microlens + Grating Coupler Simulation

• Combines FDTD (grating) + FFT-based Fresnel propagation (bulk optics)
• Analyzes microlens impact on fiber alignment tolerance
• Result: 2.3x tolerance improvement (24 μm vs 10.5 μm)
• Comprehensive tutorial with 11 visualizations