Semiconductor light emitting device having a shift thyrister with a laminated structure, exposure head, and image forming apparatus

A semiconductor light emitting device comprising:

• a plurality of nodes each connected to a gate of a shift thyristor and a gate of a light emitting thyristor;
• and
• a plurality of transfer diodes arranged so as to connect the plurality of nodes to each other,
• wherein the shift thyristor has a laminated structure including a plurality of semiconductor layers, and is provided to a mesa formed separately from the light emitting thyristor and each of the plurality of transfer diodes,
• wherein the shift thyristor includes:
• a first metal layer continuously provided so as to straddle the mesa;
• and
• a second metal layer, which is arranged above the first metal layer, and includes a first part and a second part arranged so as to be opposed to the first part across the mesa, and
• wherein the first part and the second part of the second metal layer are each electrically connected to the first metal layer in a region that does not overlap the mesa in a plan view.