Optical phased arrays are versatile components enabling rapid and precise beam steering. An integrated approach is followed in which a 1D optical phased array is fabricated on silicon-on-insulator. The optical phased array consists of 16 parallel grating couplers spaced 2 mu m apart. Steering in one direction is done thermo-optically by means of a titanium electrode on top of the structure using the phased array principle, while steering in the other direction is accomplished by wavelength tuning. At a wavelength of 1550 nm, continuous thermo-optical steering of 2.3 degrees and wavelength steering of 14.1 degrees is reported. (C) 2009 Optical Society of America