US 4,839,898 A · Optical resonating device

Abstract

An optical fiber laser comprises an optical resonant cavity defined by an optical fiber (1). First and second reflectors (8, 13; 14, 19) are optically coupled with respective ends of the fibre. The first reflector is adapted to reflect radiation at the lasing wavelength and the second reflector to be partially transparent to radiation at the lasing wavelength. Each reflector comprises a directional coupler (8; 14) having first and second pairs of ports. One each of the one pair of ports (11; 16) of each coupler (8; 14) is optically coupled with the cavity (1) while both ports of the other pair (9, 10; 17,18) are coupled with a respective loop of optical fibre (13, 19). The remaining port (12) of one coupler (8) is connected with a source of pumping radiation (6), and the remaining port (15) of the other coupler (14), is available to output laser radiation.

Claims9

Dependent claims

An optical fibre based laser device comprising an optical fiber resonant cavity having first and second reflectors for reflecting radiation at a predetermined resonating wavelength characterised in that:

at least one of said reflectors is an optical loop reflector comprising a directional optical coupler having a first and a second input and a first and a second output,
said first input being optically coupled to said optical fibre resonant cavity,
said first and second outputs being optically coupled together, and
the optical loop reflector being reflective at said resonating wavelength and at least partially transmissive at a predetermined pump wavelength.

1 more element

An optical fibre based laser device comprising:

an optical fibre resonant cavity having first and second ends;
a first optical reflector disposed at said first end of the cavity for reflecting optical signals of a first wavelength within said cavity and for passing optical signals of a second wavelength into said cavity;
a second optical reflector disposed at said second end of the cavity for partially reflecting optical signals of said first wavelength within said cavity and for partially passing optical signals of said first wavelength out of said cavity;
at least one of said optical reflectors being an optical loop reflector having
(a) a directional optical coupler having a first pair of ports A,B and a second pair of ports C,D with optical signals input to either port of one pair being coupled to the other pair of ports by a predetermined coupling co-efficient K,
(b) both parts of one of said pairs of ports being optically coupled together;
and
(c) one port of the remaining pair of ports being optically coupled to one end of said cavity;
and
(d) the other port of the remaining pair of ports being optically coupled to pass optical signals to or from said optical cavity.

7 more elements

Dependencies are inferred from the claim text.

Optical resonating device

Life of this patent

Optical resonating device

Life of this patent

Abstract

Claims9