This was an animated series broadcast in our Doordarshan channel about a couple of decades ago.
It was about a boy and dog who jumps under the carpet, after his mother switches off the light, and they go through a rainbow tunnel and emerge out from a tree trunk into a wonderland. It had a catchy background tune. After they finish their adventures they get back uncaught to the bed to sleep.
I'd like to know the title of this series or any links that might help.
That sounds a lot like Jamie and the magic torch
From wikipedia
The programme was based around the young boy of the title and his torch. When shone on the floor, the torch opened up a hole into a fun dimension called Cuckoo Land.
The beginning of each episode had Jamie's mother tucking him into bed at night and saying, "Sleep well, Jamie." Then from under his bed, his pet dog Wordsworth would appear holding the torch in his mouth. Jamie would take the torch and shine it on the floor, opening up a portal to Cuckoo Land (which Wordsworth always got stuck in). The portal manifested itself as a helter skelter.
When they reached the end of the slide, they would fly out into Cuckoo Land from the bottom of a tree trunk and land on a trampoline. All of this was accompanied by a song, written by Joe Griffiths. Once in Cuckoo Land, the fun would begin.
