The invention relates to a method and device for controlling the amplitude of the wavelength spectrum of ultra-short light pulses emitted by multipass laser amplifiers. The pair of holes are in opposing alignment with one another. The ASIC is coupled between the microprocessor and the memory and is utilized to communicate with an external computer system for downloading a program code from the external computer system to the memory in which the program code is stored in a memory region of the memory through the ASIC. A flexible member is positioned in the socket and attached to the moveable member, so that the moveable member can be controlled for placement in an out of the socket. Wall thickness from a sliding side surface of the piston to the oil gallery is set greater on a piston skirt side than on a piston top surface side. Each core layer includes a plurality of braided reinforcing fibers with the braids of reinforcing fibers aligned in a circumferential direction.