He also pointed the laser at the airport control tower.
When apprehended by police, still near the Sign of the Kiwi, admitted pointing the laser at the aircraft, but said he didn't realise it was dangerous.
Defence counsel Serena Bailey said Hemopo had written a letter of apology to control tower staff, and his partner wrote a letter to the court today.
Judge Tom Gilbert told Hemopo that his actions put the flights at "unnecessary risk".
But he accepted that his actions were "motivated by stupidity rather than [by] any malice".
Hemopo was originally scheduled to be sentenced several months ago but he failed to show up at court.
He was remanded in custody on October 17 until today.
Judge Gilbert said his prior convictions ran to several pages but included "nothing at all like this in your past".
As a serving prisoner, the only realistic sentence was one of imprisonment, the court heard.
The judge sentenced Hemopo to 10 weeks' imprisonment as a deterrent to others.
Judge Gilbert said it was up to Corrections to calculate his release date. He also ordered the destruction of the laser.