Optical filter and imaging device

An optical filter, comprising:

• an absorption layer comprising a near-infrared absorbing dye (A) satisfying the following (i-1) to (i-5), and a transparent resin;
• and a reflection layer, and the optical filter satisfying the following (ii-1), (ii-2), (ii-3) and (ii-6):
• (i-1) in a spectral transmittance curve of wavelength of 400 to 1,100 nm measured in the transparent resin, a maximum absorption wavelength λmax(A) TR is in a wavelength range of 760 to 900 nm,
• (i-2) in a spectral transmittance curve of wavelength 400 to 1,100 nm measured in the transparent resin with such a concentration that a transmittance at the maximum absorption wavelength λmax(A) TR is 10%, both an average transmittance T435-480ave (A) TR of light in a wavelength range of 435 to 480 nm and an average transmittance T480-590ave (A) TR of light in a wavelength range of 480 to 590 nm are 90% or more;
• (i-3) in a spectral transmittance curve of wavelength of 400 to 1,100 nm measured in dichloromethane, a maximum absorption wavelength λmax(A) DCM is in a wavelength range of 760 to 900 nm;
• (i-4) in a spectral transmittance curve of wavelength 400 to 1,100 nm measured in dichloromethane with such a concentration that a transmittance at the maximum absorption wavelength λmax(A) DCM is 10%, an average transmittance T435-480ave (A) DCM of light in a wavelength range of 435 to 480 nm is 95% or more and an average transmittance T480-590ave (A) DCM of light in a wavelength range of 480 to 590 nm is 97% or more;
• (i-5) a difference between the average transmittance T435-480ave (A) DCM and the average transmittance T435-480ave (A) TR, and a difference between the average transmittance T480-590ave (A) DCM and the average transmittance T480-590ave (A) TR are both 10.5% or less;
• and
• (ii-1) an average transmittance of light in a wavelength range of 800 to 900 nm is 5% or less at an incident angle of 60 degrees;
• (ii-2) an average transmittance T435-480ave0° of light in the wavelength range of 435 to 480 nm is 77% or more at an incident angle of 0 degree;
• (ii-3) an average transmittance T490-580ave0° of light in the wavelength range of 490 to 580 nm is 87% or more at an incident angle of 0 degree;
• and
• (ii-6) a wavelength λSHT20-0° that is a shorter wavelength of wavelengths showing a transmittance of 20% at an incident angle of 0 degree is in a wavelength range of 640 to 690 nm, and a difference between a wavelength λSHT20-30° that is a shorter wavelength of wavelengths showing a transmittance of 20% at an incident angle 30 degrees and the wavelength λSHT20-0° is 3 nm or less;
• wherein the near-infrared absorbing dye (A) comprises a cyanine-based dye represented by the following Formula (A1) or Formula (A2):
• wherein, symbols in Formulae (A1) and (A2) are as follows:
• R101 to R109 and R121 to R131 are each independently a hydrogen atom, a halogen atom, an alkyl group or alkoxy group having 1 to 15 carbon atoms, which may have a substituent, or an aryl group having 5 to 20 carbon atoms;
• R110 to R114 and R132 to R136 are each independently a hydrogen atom, a halogen atom, or an alkyl group or alkoxy group having 1 to 15 carbon atoms;
• a plurality of R101's to R109's and R121's to R131's included in each formula may be the same as or different from each other;
• X− represents a monovalent anion;
• n1 and n2 are 0 or 1;
• and
• a hydrogen atom bonding to a carbon ring containing —(CH2)n1— a carbon ring containing —(CH2)n2— may be substituted with a halogen atom, or an alkyl group having 1 to 15 carbon atoms or aryl group having 5 to 20 carbon atoms which may have a substituent;
• wherein the absorption layer has a thickness of 0.3 μm to 10 μm;
• and
• wherein the cyanine-based dye comprises an anion selected from the group consisting of I−, BF4−, PF6−, ClO4−, anions represented by Formulae (X1) and (X2):