High speed phase modulators for silicon photonic integrated circuits:a role for lithium niobate?

Lithium niobate(LN)has been and still is a prominent material for high speed optical modulators.The performance of such LN-modulators—as a stand-alone building block for optical systems—has been unchallenged for many years.But in many ways it has proven to be very hard to integrate lithium niobate modulators with other functions on a single optical chip.As a result,scientific interest in this material has been fading away.