Acoustic wave device, high frequency front end circuit, and communication apparatus

An acoustic wave device comprising:

• a supporting substrate;
• an acoustic reflection layer directly or indirectly on the supporting substrate;
• a piezoelectric layer directly or indirectly on the acoustic reflection layer;
• one or more IDT electrodes directly or indirectly on the piezoelectric layer;
• and
• a wiring electrode directly or indirectly on the piezoelectric layer and electrically connected to the one or more IDT electrodes;
• wherein
• the acoustic reflection layer includes:
• a first dielectric layer;
• a second dielectric layer closer to the supporting substrate than the first dielectric is to the supporting substrate and having an acoustic impedance higher than that of the first dielectric layer;
• and
• a metal layer closer to the piezoelectric layer than the first dielectric layer is to the piezoelectric layer and having an acoustic impedance higher than that of the first dielectric layer;
• and
• when the acoustic reflection layer is viewed in plan, in a region that encompasses one of the one or more IDT electrodes and a wiring electrode connected to the one IDT electrode but does not encompass any IDT electrodes other than the one of the one or more IDT electrodes, an area in which the metal layer is provided is smaller than an area in which the second dielectric layer is provided.