Audio jack optical modules that may have a reduced size. Various examples may provide an optical module for an audio jack where a driver circuit is omitted from the optical module and instead placed either elsewhere in the audio jack or separately outside the audio jack. In some examples, the driver may be integrated with a logic circuit, such as a coder-decoder (CODEC) or other logic circuit. Other examples may provide an optical module for an audio jack where a lens for a light-emitting diode is omitted. In some examples, a higher-power light-emitting diode may be used. These light-emitting diodes may be strong enough to provide a requisite amount of light to a detector in, or associated with, an audio plug.