Chief Justice Sanjay Kishan Kaul administered the oath of office to Justice Authinathan.
Advocate General Muthukumaraswamy and other Bar leaders welcomed the newly sworn in Judge.
With this, the sitting strength of the high court will go up to 39, as against the sanctioned strength of 75.
Authinathan, Principal Sessions judge of Chennai who retired on January 19 this year, was elevated and appointed additional judge of the high court after a notification to this effect was received by the court from the Union Law Ministry Law on September 1.