Acoustically tunable wavelength filter with gain

The first integrated optical amplifying acoustically tunable wavelength filter in Er-doped LiNbO/sub 3/ is reported. At the signal wavelength of /spl lambda//sub s/=1531 nm a maximum gain of 4.8 dB has been obtained with a coupled pump power of 160 mW (/spl lambda//sub p/=1484 nm). Lossless signal transmittance has been achieved with a pump power as low as 13.5 mW for /spl lambda//sub s/>1561 nm.>