Optical Interferometer (Artacho)

Optical Interferometer
Gruppe Markus Arndt (Universität Wien)

About the piece:
Self Image is an orchestral piece inspired by the fractal patterns produced by near-field diffraction in an optical interferometer. The score aims to reproduce this intricate structure -also called Talbot carpet-  by having the sound masses develop in the same way waves interfere, that is by adding or canceling each other.  At the beginning of the piece, we can hear three periodic laser pulses as recorded by physicists of the OTIMA-team (lead by Prof. Markus Arndt) during running a matter wave interferometer in the time domain, only slowed 100 times to make them audible (see bottom of the page). 

The sound then increases until reaching a critical mass point (0'30") where a periodic sequence begins in which all musical processes develop accurately in the same way the Talbot Carpet does. That sequence is heard twice (1'15") until it then gradually vanishes, leaving only the pulses  which underline the whole piece.

In order to translate complexity into musical parameters, harmonic entropy -the amount of dissonance, of different simultaneous partials in the sound mass- increases as the sequence evolves, reaching a maximum point (1'00" and again 1'45") towards the middle of it, only to resolve back in the clearer -more harmonic- sounds that are heard at the 'rest point' at the beginning of the sequence.

This piece was written and conceived through the intense collaboration with Dr. Haslinger and auspiced by CoQuS (Vienna Doctoral Program on Complex Quantum Systems) and the Vienna University of Technology. I would like to thank specially my friend and colleague Andreas Olszewski for producing the virtual score with the help of virtual instruments.