Fotona Lightwalker ATS Laser Fotona’s patented QSP (Quantum Square Pulse) mode* allows the laser to ablate more efficiently and with greater precision. The improved ablation efficacy of QSP mode indicates that more of the laser energy is used for cutting and less is absorbed by the interfering debri or sub-ablation threshold of the surrounding dental tissues. This provides the means for improved cutting speed, finesse and comfort when treating hard and soft dental tissues.