A British man who was found with blueprints for a rocket in his luggage at Luton Airport has been jailed for three-and-a-half years.
Yassin Nassari and his wife were arrested in May 2006
Yassin Nassari, 28, from Ealing, west London, was earlier found guilty at the Old Bailey of possessing documents likely to be useful to a terrorist.
His Dutch wife, Bouchra El Hor, 24, was cleared of failing to disclose information about terrorism.
The couple and their baby were stopped at the airport in May last year.
They were returning from trips to Syria and Holland.
Nassari, a teacher, businessman and student of Arabic, was found not guilty of the more serious offence of possessing articles for terrorist purposes.
Sentencing him, Judge Gerald Gordon said: "I have come to the conclusion that, sadly, like a number of young Muslims, you have somehow been indoctrinated into beliefs supporting terrorism by others.
Nassari had blueprints for a home-made steel rocket
"I have no doubt you wanted to immerse yourself in this fundamentalist trash, but in the material available to me there is nothing to indicate that any actual terrorist use would have been made of it by anyone."
Nassari's hard drive contained documents about martyrdom and weapons training, as well as instructions on how to construct the Qassam artillery rocket - a home-made steel rocket used by terrorist groups in the Middle-East.
He denied knowledge of the material saying he had lent his computer to another man.
Police also found several graphic videos of terrorist attacks and beheadings at Nassari's home.
There were also computer files containing documents entitled: "Preparing the fighter who is going for jihad"; "Virtues of martyrdom in the path of Allah"; "Taking care of the family left behind by the fighter" and "How to run a training camp".
The investigation, codenamed Operation Bivalve, also revealed that Nassari had communicated with other extremists via internet chat-rooms using the name "Mock Turtle".
Among them was a man known as "Abu Dujanah". Dujanah was actually Tariq al-Daour who was jailed at Woolwich Crown Court in June 2007 for incitement to murder using the internet.
Terror training manuals and videos were found at Nassari's home
'Useful to terrorists'
The trial also heard that Nassari had a letter from his wife in which she appeared to be encouraging him to become a terrorist martyr.
The court was told it read: "I am so proud of my husband. I am happy that Allah has granted you the chance to be a martyr...Maybe one day I can follow you.
"If I can't, I will send our son to you so he can follow his father's footsteps."
But Mrs El-Hor said the letter was a work of fiction and she knew nothing about what Nassari was doing.
Deputy Assistant Commissioner Peter Clarke, head of the Metropolitan Police's Counter-Terrorism Command, said: "Nassari held the ideology, ability and determination to find and download material which would have been useful to terrorists.
"What he intended to do upon his return to the UK is unclear. However, it is possible that his research could have ended up in the hands of individuals or groups willing to put it into practice."