Method and apparatus for measuring wavelength jitter of light signal

An apparatus for detecting wavelength change of a light signal comprising:

• a. means for dividing the light signal into first and second lights;
• b. first means for causing the first light to travel along a first optical path having a first index of refraction that varies with wavelength over a wavelength band;
• c. second means for causing the second light to travel along a second optical path having a second index of refraction that is relatively constant over the wavelength band;
• d. means for combining the first and second lights into an output light, the output light exhibiting a change in interference as wavelength of the light signal changes;
• and
• e. means for detecting the change in the interference as the wavelength of the light signal changes.

An apparatus for detecting wavelength jitter comprising:

• a. an amplitude splitting interferometer comprising first and second optical paths, the first optical path having a first index of refraction that varies with wavelength over a wavelength band, the second optical path having a second index of refraction that is relatively constant over the wavelength band, such that in operation first and second light signals enter and exit the amplitude splitting interferometer, whereby first and second interference light is formed;
• b. a light modulator optically coupled to the amplitude splitting interferometer such that in operation the light modulator separates the second interference light from the first interference light;
• and
• c. a detector optically coupled to the light modulator such that in operation the detector detects wavelength jitter from the first interference light.

An apparatus for detecting wavelength jitter comprising:

• a. a light modulator such that in operation the light modulator couples to first and second light signals and further such that in operation the light modulator separates the second light signal from the first light signal;
• b. an amplitude splitting interferometer coupled to the light modulator, the amplitude splitting interferometer comprising first and second optical paths, the first optical path having a first index of refraction that varies with wavelength over a wavelength band, the second optical path having a second index of refraction that is relatively constant over the wavelength band, such that in operation the first light signals enters and exits the amplitude splitting interferometer, whereby an interference light is formed;
• and
• c. a detector optically coupled to the amplitude splitting interferometer such that in operation the detector detects wavelength jitter from the interference light.

An interferometer comprising:

• a. a first beam splitter;
• b. a first optical path optically coupled to the first beam splitter and having a first index of refraction that varies with wavelength over a wavelength band;
• c. a second optical path optically coupled to the first beam splitter and having a second index of refraction that is relatively constant over the wavelength band;
• and
• d. a second beam splitter optically coupled to the first and second optical paths such that in operation an incident light enters the first beam splitter and exits the second beam splitter, whereby an output light is formed, and further such that in operation a change in wavelength of the incident light within the wavelength band causes a change in interference of the output light.

An interferometer comprising:

• a. means for dividing an incident light into first and second lights;
• b. first means for causing the first light to travel along a first optical path having a first index of refraction that varies with wavelength over a wavelength band;
• c. second means for causing the second light to travel along a second optical path having a second index of refraction that is relatively constant over the wavelength band;
• and
• d. means for combining the first and second lights into an output light, the output light exhibiting a change in interference as wavelength of the incident light changes.