Draw a Waveguide Ring Resonator

A ring resonator is an annular waveguide brought close enough to a straight bus waveguide that light couples between them across a narrow air gap. Glyph's photonics library ships this as one parametric component — ring plus bus, both single-layer — so you set a radius, a core width, and a coupling gap instead of drawing the geometry by hand.

Time: ~8 min

You'll need: Glyph open, with an active layer chosen for the waveguide core.

1. Open the Components panel and set its library dropdown to Passive photonics.
2. Click the "Ring resonator (all-pass)" card in the Resonators category. This arms it for placement — a ghost follows your cursor on the canvas.
3. Set the parameters in the Properties panel: Ring radius (default 10 µm), Core width (default 0.5 µm), and Coupling gap (default 0.2 µm). The gap is measured edge-to-edge between the ring's outer wall and the bus waveguide, not centreline-to-centreline.
4. Click the canvas to place it. Glyph generates the ring as a keyholed annulus (an outer disk minus an inner disk, via a boolean subtract) and the bus as a straight channel tangent to it below, both on your active layer.
5. Zoom in on the coupling region to confirm the gap looks right before you commit to it — a narrower gap couples more strongly (stronger, lossier resonance) than a wider one; this is a layout distance only, Glyph does not simulate optical response.
6. Route the bus into the rest of your circuit. The component exposes two ports, o1 and o2, at the bus ends — use the Connect ports button (in the same library panel) to click one port and then another on a neighbouring waveguide, and it routes and stays attached if either moves.
7. Need more coupling length? Swap in the "Racetrack resonator" card instead — same radius/gap parameters plus a Straight length for an extended straight coupling section, for a stronger or more tunable coupling than a bare circle allows.

What you built

A ring resonator: an annular waveguide plus its coupled bus, generated as one component with an explicit coupling-gap parameter, with ports ready to route into a larger photonic circuit.

Next steps

Before you route more waveguides through it, check which layer the ring landed on and how it's coloured against the rest of your mask — see Layers. To reshape or move pieces of it after placement, see Modify shapes. For where a finished photonic layout goes next, read NANYTE's maskless lithography overview, or open the editor and place a ring yourself.