Electro-optical Synergy (elos) is a method of hair removal featured in devices by 
Syneron Medical.
Below are some recent published reports:
Combination Radiofrequency and Light Energies: Electro-optical Synergy Technology in Esthetic Medicine. Sadick Neil S. Dermatologic Surgery, Volume 31 Issue s3, Pages 1211 – 1217
Hair removal using a combination radio-frequency and intense pulsed light source. [PDF] D Yaghmai, JM Garden, AD Bakus, EA Spenceri, GJ … – Journal of Cosmetic and Laser Therapy, 2004
Blond hair removal using ELOS systems. C Schroeter, S Sharma, N Mbonu, T Reineke, H … – Journal of Cosmetic and Laser Therapy, 2006
Combination of short-and long-pulsed mode of electro-optical synergy technology for photoepilation: …
S Karsai, L Schmitt, C Raulin, S Hammes – J Eur Acad Dermatol Venereol, 2008
Lasers, lights and related technologies: a review of recent journal highlights
RF Bipolar – Viewpoints in dermatology, 2007
Photoepilation: a growing trend in laser-assisted cosmetic dermatology.
K Nouri, V Vejjabhinanta, SS Patel, A Singh – Journal of Cosmetic Dermatology, 2008