- "There's an inertial confinement laser barrier down there, which is cool."
- ―Billy Koenig
The Inertial Confinement Laser Barrier is a system designed by S.H.I.E.L.D. to confine or protect objects and prisoners.
Before descending to the vault, Billy Koenig taught Skye how to operate the Inertial Confinement Laser Barrier, specifically how to turn it into a soundproof barrier and an opaque screen.
During the interrogation, Skye used it to silence Ward as he kept trying to discuss topics that were not included as part of her interrogation, and Skye turned the barrier opaque moments before Ward could reveal to her that he knew things about her father.
Leo Fitz also used the barrier as an air filter to reduce the oxygen inside the cell, so that Ward could experience the same hypoxia effects he suffered when Ward ejected Fitz and Jemma Simmons from the Bus inside a Medical Pod. As Ward revealed Fitz critical information regarding Donnie Gill's brainwashing in order to save Skye, Fitz allowed Ward's survival.
Phil Coulson activated the Barrier when he wanted to stop the conversation Skye and Grant Ward were having, as Skye already had the needed information and she was becoming emotional over what Ward was saying about her father. 
The Laser Barrier was used to keep Skye inside Vault D when Phil Coulson contained her after his session with the Theta Brain-Wave Frequency Machine, remembering his time as head agent of Project T.A.H.I.T.I. Melinda May told her to lock up Coulson because he was acting erratically. He pushed her inside, activated the Barrier, and turned it soundproof as he went to confront Hank Thompson about the symbols that he and the former patients of the project were writing even though their memories were changed by the Memory Overwriting Machine.
As Sunil Bakshi activated the cyanide pill in his cheek to commit suicide during his interrogation with Bobbi Morse, Lance Hunter had to deactivate the Laser Barrier to get to him and allow Jemma Simmons to save him.
Skye and Melinda May went into Vault D so that May could help Skye to calm down and regain control over her earthquake generating power. May activated the Barrier to stop the pursuit of Sif who wanted to kill Skye upon discovering that she was an Inhuman. Sif used her sword to cut through the Barrier to get to the agents.
In chronological order:
- Agents of S.H.I.E.L.D.
- ↑ Agents of S.H.I.E.L.D.: 2.01: Shadows
- ↑ Agents of S.H.I.E.L.D.: 2.03: Making Friends and Influencing People
- ↑ Agents of S.H.I.E.L.D.: 2.06: A Fractured House
- ↑ Agents of S.H.I.E.L.D.: 2.07: The Writing on the Wall
- ↑ Agents of S.H.I.E.L.D.: 2.08: The Things We Bury
- ↑ Agents of S.H.I.E.L.D.: 2.12: Who You Really Are