Disclosed herein are compounds of Formula that include a sulfonate ester, ester or ether group. The snare side head 13 has a plurality of through-holes 13c. The width Wb of the main element 26a, the transmission factor Pb of the main element 26a with respect to the reading light, the width Wc of the secondary element 27a, and the transmission factor Pc of the secondary element 27a with respect to the reading light are determined so that they satisfy a condition equation of 1.