Disclosed is a method of producing a hologram through a two-beam laser
interfering exposure process, which comprises emitting a coherent laser
light with a pulse width (.tau.) ranging from greater than 900
femtoseconds to 100 picoseconds and a laser power of 10 .mu.J/pulse or
more using a solid-state laser as a light source, dividing the pulses
light from the laser into two beams, controlling the two beams temporally
and spatially in such a manner that the two beam are converged on a
surface of or inside a workpiece for recording a hologram while matching
the respective converged spots of the two beams with one another
temporally and spatially to create the interference therebetween so as to
record a surface-relief hologram on the surface of the workpiece or an
embedded hologram inside the workpiece in an irreversible manner. The
present invention can solve a problem with a conventional process of
recording a hologram in a non-photosensitive material in an irreversible
manner using interfering femtosecond laser pulses, specifically,
distortion in the waveforms of pulsed laser beams and resulting
instability in recording of an embedded hologram due to a non-linear
optical interaction between the femtosecond laser pulses and air/the
material.