The helicopter was trying to find a vulnerable missing person in the Daventry area.
It carried on with its mission while a police car was dispatched to investigate the laser. Officers were unable to find out who was responsible.
Pilot Paul Atherton said it was "very distracting".
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He said: "On the police helicopter, I'm the only pilot.
"If I get hit in the eye and I'm blinded, who's going to fly the aircraft? People on the ground don't realise how serious this is."
The National Police Air Service (NPAS) said Mr Atherton saw two flashes of light from the laser at about 23:00 BST on Friday.
The NPAS reported 35 laser incidents on its aircraft in 2014 and 91 in 2015.
There was a total of 1,400 attacks on aircraft reported to the Civil Aviation Authority last year.
People have been jailed in the past for pointing lasers at aircraft in the sky, but the devices themselves remain legal.
Pat Lawrence, a spokesman for the British Airline Pilots Association (Balpa), said regulations need to change.
He said: "There's no restriction on the imports of these very powerful lasers."
The pilot of a police helicopter has called for a ban on lasers after a beam of light was shone at his aircraft as it flew over Northamptonshire.