CURABLE RESIN COMPOSITION FOR LENS, CURED PRODUCT, DIFFRACTION OPTICAL ELEMENT, MULTI-LAYERED DIFFRACTION OPTICAL ELEMENT

To provide a curable resin composition for a lens enabling acquisition of a cured product which enables wavelength dependence of a refractive index thereof be controlled to a desired level from near-infrared rays to short wavelength-infrared rays, and enables production of a cured product exhibiting high transmittance in the wavelength region, and to provide a cured product, a diffraction optical element, and a multi-layered optical element each obtained using the curable resin composition for a lens.SOLUTION: A curable resin composition for a lens is provided, including a dye A having maximum absorption at a wavelength of 520-620 nm, wherein wavelength dispersion WD calculated by the following expression (X) of the cured product of the composition is 2.0×10-5 or more. A cured product, a diffraction optical element and a multi-layered optical element each obtained by using the curable resin composition for a lens are also provided. Expression (X): WD=(nC-n(1129))/(1129-656). In the expression, nC represents a refractive index at a wavelength of 656 nm, and n(1129) represents a refractive index at a wavelength of 1,129 nm.SELECTED DRAWING: None 【課題】近赤外から短波赤外の波長域に亘って、屈折率の波長依存性を所望のレベルに制御でき、かつこの波長域において高い透過率を示す硬化物を得ることができるレンズ用硬化性樹脂組成物、これを用いた硬化物、回折光学素子及び多層型回折光学素子を提供する。【解決手段】レンズ用硬化性樹脂組成物であって、この組成物は波長５２０～６２０ｎｍに極大吸収を有する色素Ａを含み、この組成物の硬化物の、下記式（Ｘ）により算出される波長分散ＷＤが２．０×１０－５以上である、レンズ用硬化性樹脂組成物、これを用いた硬化物、回折光学素子及び多層型回折光学素子。ＷＤ＝（ｎＣ－ｎ（１１２９））／（１１２９－６５６）；式（Ｘ）上記式中、ｎＣは波長６５６ｎｍにおける屈折率を示し、ｎ（１１２９）は波長１１２９ｎｍにおける屈折率を示す。【選択図】なし