A control device comprising: receiving means for receiving a signal from an imaging core including an optical transceiver and an ultrasound transceiver; determination means for determining whether or not it is in a state where the ultrasound transceiver is able to properly execute transmission and reception, based on - a signal from the optical transceiver and a signal from the ultrasound transceiver which are received by the receiving means, - or the signal from the ultrasound transceiver which are received by the receiving means; and control means for performing control so that an optical path length adjustment for imaging with the optical transceiver is executed when the determination means determines that the ultrasound transceiver is able to properly execute transmission and reception, wherein the control device further comprises: detection means for detecting a connection of a catheter accommodating the imaging core, wherein the determination means executes determination processing in response to detecting the connection of the catheter by the detection means, wherein when the signals received from the ultrasound transceiver include a reflected signal or multiple reflected signals from an inner surface and an outer surface of a catheter sheath, the determination means determines that it is in a state where the ultrasound transceiver is able to properly execute the transmission and reception. receiving means for receiving a signal from an imaging core including an optical transceiver and an ultrasound transceiver; determination means for determining whether or not it is in a state where the ultrasound transceiver is able to properly execute transmission and reception, based on - a signal from the optical transceiver and a signal from the ultrasound transceiver which are received by the receiving means, - or the signal from the ultrasound transceiver which are received by the receiving means; and - a signal from the optical transceiver and a signal from the ultrasound transceiver which are received by the receiving means, - or the signal from the ultrasound transceiver which are received by the receiving means; and control means for performing control so that an optical path length adjustment for imaging with the optical transceiver is executed when the determination means determines that the ultrasound transceiver is able to properly execute transmission and reception, wherein the control device further comprises: detection means for detecting a connection of a catheter accommodating the imaging core, wherein the determination means executes determination processing in response to detecting the connection of the catheter by the detection means, wherein when the signals received from the ultrasound transceiver include a reflected signal or multiple reflected signals from an inner surface and an outer surface of a catheter sheath, the determination means determines that it is in a state where the ultrasound transceiver is able to properly execute the transmission and reception. detection means for detecting a connection of a catheter accommodating the imaging core, wherein the determination means executes determination processing in response to detecting the connection of the catheter by the detection means, wherein when the signals received from the ultrasound transceiver include a reflected signal or multiple reflected signals from an inner surface and an outer surface of a catheter sheath, the determination means determines that it is in a state where the ultrasound transceiver is able to properly execute the transmission and reception.