Police said they were using the aircraft to trace Stuart Aiken who had gone missing from York when a laser was trained at the helicopter from the area of Ouse Bridge.
Officers in the helicopter guided officers on the ground to two suspects, a man aged 46 and a woman aged 29, who were arrested on the bridge on suspicion of endangering an aircraft.
The pair, who are of no fixed address, remain in police custody for questioning.
Inspector Andy Godfrey, of York Neighbourhood Policing Team, said: "It goes without saying how dangerous it is to distract or try to blind a aircraft pilot. The consequences could have been catastrophic for the crew and members of the public on the ground.”
The incident happened at around 2.45am today and involved a helicopter crew from The National Police Air Service, based in West Yorkshire.
North Yorkshire Police, who were leading the search for missing Mr Aiken, said they had since found him in the Osbaldwick Link Road area of York and that he was receiving "appropriate medical treatment".