Infra-red is just heat by another name.
Unfortunately, advertisers and marketeers try to convince folk that it is the latest all-singing-all dancing 'thing'. It's not. It has been around since time began.
Infra-red is emitted from all cookers, hobs, ovens, candles, light bulbs, electric fires, real-flame fires, gas fires, paraffin heaters, convector heaters, fan heaters, hair dryer, central heating, vacuum cleaner, iron, toaster, kettle, car engine, the Sun, volcanoes, hot springs, you, the cat, and your cup of coffee.
Some microwave ovens combine a grill or convection elements to brown the food. These can be conventional metal elements, or possibly quartz-halogen tubes. Some microwave ovens have turbo fan forced air heating.