Ultrasound transducers, one of the most widely used sensors in the era of the fourth Industrial Revolution, have been recognized and used in a variety of industries including medical, automotive, and robotics. In particular, recent research has focused on the development of multi-mode imaging systems that combine ultrasound and optical imaging to improve the accuracy of information acquisition. Unfortunately, its efficient combination has been severely limited due to the inherent opacity of conventional ultrasound transducers. These limitations cause off-axes between the ultrasound (US) and optical signal paths, resulting in low signal-to-ratio and bulky system. This is especially a critical problem for a photoacoustic (PA) imaging system that requires the ultrasonic transducer to detect the photoacoustic signal. Here, we introduce a newly developed optically transparent ultrasound transducer (TUT) to overcome the limitation. We combined the developed TUT with an optical resolution photoacoustic microscopy (OR-PAM). Using a mouse, we successfully acquired in vivo PA and US images and confirmed the feasibility of the TUT and TUT integrated OR-PAM system.