We present the 1.9–4.2 \micron spectra of the five bright ( L \leq 11.2 ) young stars associated with silhouette disks with moderate to high inclination angle of 39–80 \arcdeg in the M42 and M43 regions .
The water ice absorption is seen toward d121-1925 and d216-0939 , while the spectra of d182-316 , d183-405 , and d218-354 show no water ice feature around 3.1 \micron within the detection limits .
By comparing the water ice features toward nearby stars , we find that the water ice absorption toward d121-1925 and d216-0939 most likely originates from the foreground material and the surrounding disk , respectively .
The angle of the disk inclination is found to be mainly responsible for the difference of the optical depth of the water ice among the five young stars .
Our results suggest that there is a critical inclination angle between 65 \arcdeg and 75 \arcdeg for the circumstellar disk where the water ice absorption becomes strong .
The average density at the disk surface of d216-0939 was found to be 6.38 \times 10 ^ { -18 } g cm ^ { -3 } .
The water ice absorption band in the d216-0939 disk is remarkable in that the maximum optical depth of the water ice band is at a longer wavelength than detected before .
It indicates that the primary carrier of the feature is purely crystallized water ice at the surface of the d216-0939 disk with characteristic size of \sim 0.8 \micron , which suggests grain growth .
This is the first direct detection of purely crystallized water ice in a silhouette disk .