Massachusetts Institute of Technology

Kyungwon An

Michael S Feld

Richard P Rava

Rebecca Rae Richards-Kortum

Carter Kittrell

Ramachandra Rac Dasari

Joseph J Baraga

Paola Taroni

Robert M Cothren

Lucene Tong

Young D Park

Anand V Mehta

Ramachandra Rao Dasari

James J Childs

In a single-atom microlaser, a pair of opposed reflectors define a high-finesse or 'high-Q' optical cavity therebetween. A source delivers a stream of multiple-energy-level atoms or particles into the cavity. Each individual atom in the stream is excited by a pump from a lower energy level to an upper energy level before injection into the cavity. The cavity resonance frequency is substantially matched to the frequency of a photon emitted by each atom as it enters the cavity. The photon is emitted due to a transition in energy between the upper level and lower level of each atom. In this manner, upon entry of a sequence of individual atoms into the cavity for example, the average number of photons resonating in the cavity exceeds one and the average number of atoms in the cavity is less than one. The photons are sustained in the high-Q cavity for a long enough time period such that the photon field interacts with the next atom in the stream. A beam of coherent light in the optical frequency spectrum is emitted from the cavity.

Microlaser

A method for laser induced fluorescence of tissue in which laser radiation is used to illuminate and induce fluorescence in the tissue under study to determine the chemical composition or pathologic condition of tissue. The laser radiation and the retrieved fluorescing radiation can be conveyed through a catheter using an array of optical fiber. The fluorescence spectrum of the tissue can be displayed and analyzed to obtain information regarding the chemical composition and medical condition of the tissue inside the human body.

Method for laser induced fluorescence of tissue

Growing community of inventors

Cambridge, MA, United States of America

Kyungwon An