Optical filter and imaging device

Abstract

The filter (10) of the present invention sequentially comprises a first dielectric multilayer film (200), a resin layer (210), a second dielectric multilayer film (220), a near-infrared absorbing glass (100), and a third dielectric multilayer film (230). Its coefficient of thermal expansion is 80×10⁻⁷ / K to 120×10⁻⁷ / K, and its fracture toughness is 0.35 MPa・√m to 0.55 MPa・√m. A first mirror layer (110) is disposed on the side of the second dielectric multilayer film (220). The linear roughness of the first mirror layer (110) is less than 0.5 μm, and the linear roughness of the crack layer (130) is 0.5 μm to 1.5 μm. A second mirror layer (120) is disposed on the side of the third dielectric multilayer film (230), and the width of the crack layer (130) is 40 μm to 80 μm. μm, the crack layer (130) has more than 3 surface roughness peaks in the width direction, and the distance between the peaks is less than 35 μm.

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