Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I): ##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2): ##STR00002## wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I): ##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2): ##STR00002## wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

##STR00002## wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

##STR00002## wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

?R.sup.10a?.sub.mSH(i-1)

?R.sup.11a?.sub.nS?R.sup.12aS?.sub.pR.sup.13a(i-2) wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

?R.sup.10a?.sub.mSH(i-1)

?R.sup.11a?.sub.nS?R.sup.12aS?.sub.pR.sup.13a(i-2) wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

An optical modulator includes an organic solid crystal thin film having an organic molecule and an electron withdrawing group (EWG) bonded to the organic molecule, a primary electrode disposed over a first region of the organic solid crystal thin film, and a secondary electrode disposed over a second region of the organic solid crystal thin film, wherein an optical property of the organic solid crystal thin film is configured to change in response to a changing voltage between the primary electrode and the secondary electrode.

An optical modulator includes an organic solid crystal thin film having an organic molecule and an electron withdrawing group (EWG) bonded to the organic molecule, a primary electrode disposed over a first region of the organic solid crystal thin film, and a secondary electrode disposed over a second region of the organic solid crystal thin film, wherein an optical property of the organic solid crystal thin film is configured to change in response to a changing voltage between the primary electrode and the secondary electrode.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

?R.sup.10a?.sub.mSH(i-1)

?R.sup.11a?.sub.nS?R.sup.12aS?.sub.pR.sup.13a(i-2) wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.

Provided is an additive for imparting ultraviolet absorbency, or an additive for imparting a high refractive index, which has satisfactory compatibility with a resin serving as a matrix and can maintain high transparency even if added in high concentrations. Also provided is an additive with which the function of imparting both ultraviolet absorbency and a high refractive index can be realized by means of one kind of additive. This additive is represented by the following Formula (I):

##STR00001## wherein at least one of R.sup.1a to R.sup.9a is a monovalent sulfur-containing group represented by the following Formula (i-1) or Formula (i-2):

?R.sup.10a?.sub.mSH(i-1)

?R.sup.11a?.sub.nS?R.sup.12aS?.sub.pR.sup.13a(i-2) wherein R.sup.10a to R.sup.12a each represent a divalent hydrocarbon group or the like; and R.sup.13a represents a monovalent hydrocarbon group or the like.