A craser device, imaging system utilizing a craser device, and a method of imaging. The craser device includes a gain medium with excited gain medium atoms that emit x-ray and/or gamma-ray photons, a transmission medium abutting the gain medium, and a reflecting mirror comprising one or more lower refractive index layers and abutting the transmission medium. The transmission medium has a higher refractive index than the gain medium and at least one of the materials in the reflecting mirror. The x-ray and/or gamma-ray photons are confined to the transmission medium via total internal reflection and interact multiple times with the excited gain medium atoms through evanescent waves producing amplified stimulated emission leading to formation of a high intensity incoherent or coherent x-ray and/or gamma-ray beam.