**Abstract**

In this chapter we will describe a new development of combinatorial pulsed laser deposition (CPLD) which targets the exploration of interface libraries. The idea is to modulate continuously the composition of interfaces on a few atomic layers in order to alter their functional properties. This unique combinatorial synthesis of interfaces is possible due to very specific PLD characteristics. The first one is its well-known ability for complex oxide stoichiometry transfer from the target to the film. The second one is the layer by layer control of thin film growth at the atomic level using in-situ RHEED characterization. The third one relates to the directionality of the ablated plume which allows for selective area deposition on the substrate using a mobile shadow-mask. However PLD also has some limitations and important PLD aspects to be considered for reliable CPLD are reviewed. Multiple examples regarding the control of interface magnetism in magnetic tunnel junctions and energy band and Schottky barrier height tuning in ferroelectric tunable capacitors are presented.

**Keywords:** combinatorial synthesis, oxide thin films and multilayers, functional heterostructure
