We investigate time evolution of optical conductivity in the half-filled one-dimensional extended Hubbard model driven by a transient laser pulse, by using the time-dependent Lanczos method. Photoinduced in-gap excitations exhibit qualitatively different structure in the spin-density wave (SDW) in comparison to the charge-density wave (CDW) phase. In the SDW, the origin of a lowenergy in-gap excitation is attributed to even-odd parity of photoexcited states, while in the CDW an in-gap state is due to confined photo-generated carriers. The signature of the in-gap excitations can be identified as a characteristic oscillation in the time evolution of physical quantities.