PK Mukherjee

Who is not seized of the wondrous powers of the laser! It has applications in a wide range of fields such as communications, industry, medical science, defence and space science. Thanks to technological advancements, it has become possible to develop both continuous and pulsed lasers. In a continuous laser, laser light is emitted continuously, whereas in a pulsed laser, it is emitted intermittently in a pulsed manner.

It is possible to get a pulsed laser using some special techniques such as Q-switching, ‘mode locking’, etc. Pulsed laser using Q-switching has a duration, which is of the nanosecond order (10-9 seconds), while the pulsed laser obtained through mode locking has a duration of the order of picoseconds (10-12 seconds). Scientists have succeeded in obtaining laser pulses with durations as short as femtoseconds (10-15 seconds) using a special technique called Chirped Pulse Amplification (CPA). The laser obtained through this process has a power of several terawatts (1012 Watts) magnitude. Pulsed lasers have specialised applications in many areas of research importance…read more on NOPR