A device for the production of holographic reconstructions having light modulators is disclosed. The light guiding member is a rod-shaped member that guides light in a longitudinal direction thereof. The belt surrounds a portion of the inner housing. The phase detector output signals are balanced and of uniform width, minimizing oscillator control signal ripple in the clock data recovery circuit, while the linearity of the phase detector makes its output predictable. The retention section of the contact securely holds the coil spring in its place.