Amplifying voltage from an inductor
You have an L2 inductance of 15 mH that is somewhat lightly coupled to L1 (k = 0.05) hence, the induced voltage in L2 is virtually all in series with the self inductance of L2 (15 mH). This forms a very resonant tuned circuit with the input capacitance of the op-amp (1.5 pF for an LT1818) and that very resonant frequency is 1.06 MHz.

That 1.06 MHz looks in the same ballpark to the ripple artifacts I see in the signal in your picture. You might argue that you are applying a sinewave and hence there should be no harmonics to stimulate resonant signals but, your time-base starts at t=0 and the introduction of a sinewave at t=0 will produce harmonics. Maybe wait for 100 us and see if the ripples start to die down?

It's also worth pointing out that I see some evidence of "artifacts" in the original waveform but I note that L1 and L2 are only 0.2 mH. You have to be consistent with these things and remember that it is likely that your spice sim will have a default value of capacitance attached to every node in your circuit.