Laser module

A laser module comprising:

• a quantum cascade laser element including:
• a substrate;
• a first clad layer provided on the substrate;
• an active layer provided on an opposite side of the first clad layer from the substrate and configured to generate a terahertz wave having a difference frequency between a first frequency and a second frequency;
• and a second clad layer provided on an opposite side of the active layer from the first clad layer;
• and
• a support member configured to support the substrate of the quantum cascade laser element and propagate the terahertz wave, wherein
• the quantum cascade laser element includes:
• a first end surface located on a first side in a second direction orthogonal to a first direction that is a stacking direction of the substrate, the first clad layer, the active layer, and the second clad layer;
• and
• a second end surface located on a second side opposite to the first side in the second direction,
• the substrate includes:
• a first substrate-surface that constitutes a part of the first end surface and extends along the first direction and along a third direction which is orthogonal to the first direction and the second direction;
• a second substrate-surface that constitutes a part of the second end surface;
• a third substrate-surface facing the active layer in the first direction;
• and
• a fourth substrate-surface located on an opposite side from the third substrate-surface in the first direction,
• the active layer includes:
• a first active-layer-surface that constitutes a part of the first end surface and constitutes a resonator for oscillating light of the first frequency and light of the second frequency;
• and
• a second active-layer-surface that constitutes a part of the second end surface,
• the support member includes:
• a first portion including a first surface facing at least a portion of the fourth substrate-surface;
• and
• a second portion including:
• a second surface connected to the first surface and facing at least a portion of the first substrate-surface;
• and a third surface located on an opposite side from the second surface in the second direction, and
• at least a portion of the terahertz wave generated in the active layer is incident on the second surface of the support member through the substrate and is emitted from the third surface through an inside of the second portion.