Diddy Holograms into Son's 23rd Birthday Party in L.A. from Miami

Diddy's trip to Florida prevented him from attending his son's 23rd birthday party in L.A. -- well, in-person anyway ... but when you're Diddy you just show up as a HOLOGRAM!!!

The rap mogul's handling some biz in Miami, but turned to the folks over at PORTL to have them beam him live Thursday night into his son Christian Combs' 23rd birthday soiree in Los Angeles. The visual is stunning ... Diddy appeared life-size as a 4K interactive hologram.

We're told the PORTL device allowed Diddy to see and hear the crowd. You can see he dedicated the hell out of "Happy Birthday" to his son and made a toast. Diddy's 3 daughters -- Jessie, D'Lila and Chance -- also appeared as holograms with him.

PORTL, an LA-based startup, dubs itself as the world's first and only single passenger holoportation machine ... and you know what that means. It doesn't come cheap -- it'll cost the average joe around $60k.

For his part ... Christian had one helluva bday bash -- Lil Wayne, Chris Brown, Snoop's son Cordell Broadus, Swae Lee, Winnie Harlow and Young Thug were just some of the celebs who attended. They all showed up in-person, though.