It's a logo of Spiral Bulb reduced to a bulb with a spiral light. This light bulb is like a normal bulb except the bulb part is a spiral instead.
This Spiral Bulb icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,700 icons, all in the same style and quality.