As dpham00 mentioned, "Do not disturb" option in "Sound and notification" allows one to turn off calls and alerts during specified times. That's what I have configured, and place the phone screen away from me and angled down so that any notification lights aren't visible. I think there's also an option to enable "muting" the phone when placed face down, as bassplayrguy suggests. I've used that option to "mute" calls when at work, and think it could also be an option to hide the LED notification light.