A surgical access assembly comprises a trocar and a surgical instrument. The trocar comprises a housing and an access tube extending distally from the housing. The housing comprises a hollow light emitter. The housing and the access tube define a lumen extending through the housing and the access tube. The hollow light emitter is configured to project light in the lumen. The surgical instrument comprises an end effector and a shaft extending proximally from the end effector. The shaft comprises an optical receiver positioned within reach of the light from the hollow light emitter. The shaft further comprises a light guide extending from the optical receiver along at least a portion of the shaft toward the end effector.
