Abstract: A photopyrotechnical detonating device and a photopyrotechnical chain using this device are disclosed. A pyrotechnical charge, which can be actuated by a laser beam, is placed in a solid body. The beam is conveyed by an optical fiber which penetrates a connector mounted on the body. The beam, which is divergent when it leaves the fiber, is made parallel by a first lens. A second lens, mounted on the body, makes the beam converge and works with a transparent barrier to focus the beam on a given point. Tight-sealilng means are provided between the transparent barrier and the body of the device, thus ensuring the containment of the charge. The transparent barrier is shaped like a truncated cone which maintains its integrity within a tapered cylinder after firing of the actuating and boosting charges. The tightness of the transparent barrier within the tapered cylinder is enhanced by the sealing means and prevents fragments from entering the detonating device after firing of the charges.