Spurs face their capital rivals at Wembley aiming to seal a place in May's showpiece event at the expense of Antonio Conte's Premier League leaders.
The north Londoners have lifted the trophy on eight separate occasions but have failed to appear in a final since 1991.
Chelsea have enjoyed significantly more success in recent years, having won the tournament four times in the last decade, and Pochettino is keen for his players to make the most of the occasion.
"For us it's a final and we need to show that from the first moment of the game. We need to play aggressive, with our philosophy and mentality," Pochettino told his pre-match press conference.
"To have the possibility to play a semi-final against one of the best teams in Europe doesn't happen much and I think it's a great opportunity.
"It is most important to be 100% focused on the game and be better than them.
"It will be a very tough game. They have great manager and players."
Spurs are set to go into the game in a rich vein of form, having won seven consecutive top-flight fixtures in recent weeks.
Chelsea have lost two of their last four games but Pochettino is adamant it is the Blues who should be regarded as the favourites to progress.
Hugo Lloris is expected to come into the team ahead of the stricken Dutchman but full-back Danny Rose has lost his battle to be fit to feature at England's national stadium.