Wavelength dispersion measuring apparatus and polarization dispersion measuring apparatus

A wavelength dispersion measuring apparatus comprising:

• a first tunable wavelength pulse light source;
• an optical demultiplexer for demultiplexing a first optical pulse emitted from said first pulse light source into a reference optical pulse and an incident optical pulse to be sent into an object to be measured;
• an optical multiplexer for multiplexing the reference optical pulse and an outgoing optical pulse passing through the object to output multiplexed light;
• a second pulse light source for emitting a second optical pulse synchronous with a repeating frequency of the first optical pulse emitted from said first pulse light source;
• spatial optical delay means for changing a relative phase of the second optical pulse with respect to the first optical pulse;
• sampling means for receiving the multiplexed light and the output second optical pulse from said optical delay means to obtain, whenever the relative phase of the second optical pulse is changed, a correlation intensity signal proportional to an optical waveform of the multiplexed light in that phase;
• and
• signal processing means for obtaining the optical waveform of the multiplexed light from the correlation intensity signal obtained by said sampling means,
• wherein wavelength dispersion of the object is obtained by measuring a delay time of the outgoing optical pulse passing through the object on the basis of intervals between peaks of the optical waveform of the multiplexed light.

A polarization dispersion measuring apparatus comprising:

• a first tunable wavelength pulse light source driven by a reference signal;
• an optical demultiplexer for demultiplexing a first optical pulse emitted from said first pulse light source into a reference optical pulse and an incident optical pulse to be sent into an object to be measured;
• an analyzer for passing a component in a specific polarization direction of an outgoing optical pulse passing through the object;
• an optical multiplexer for multiplexing the reference optical pulse and the outgoing optical pulse passing through the object and said analyzer to output multiplexed light;
• a second pulse light source for generating a second optical pulse which is synchronous with the first optical pulse and delays a predetermined time for each period of the first optical pulse;
• sampling means for receiving the multiplexed light and the second optical pulse to obtain an optical pulse train signal proportional to an intensity of the multiplexed light obtained in synchronism with the second optical pulse;
• and
• signal processing means for obtaining, from the optical pulse train signal from said sampling means, an envelope formed by peaks of individual optical pulses forming the optical pulse train,
• wherein polarization dispersion of the object is obtained by measuring a delay time of the outgoing optical pulse passing through the object on the basis of intervals between the peaks of the envelope.

A polarization dispersion measuring apparatus comprising:

• a first tunable wavelength pulse light source;
• an optical demultiplexer for demultiplexing a first optical pulse emitted from said first pulse light source into a reference optical pulse and an incident optical pulse to be sent into an object to be measured;
• an analyzer for passing a component in a specific polarization direction of an outgoing optical pulse passing through the object;
• an optical multiplexer for multiplexing the reference optical pulse and the outgoing optical pulse passing through the object and said analyzer to output multiplexed light;
• a second pulse light source for emitting a second optical pulse synchronous with a repeating frequency of the first optical pulse emitted from said first pulse light source;
• spatial optical delay means for changing a relative phase of the second optical pulse with respect to the first optical pulse;
• sampling means for receiving the multiplexed light and the output second optical pulse from said optical delay means to obtain, whenever the relative phase of the second optical pulse is changed, a correlation intensity signal proportional to an optical waveform of the multiplexed light in that phase;
• and
• signal processing means for obtaining the optical waveform of the multiplexed light from the correlation intensity signal obtained by said sampling means,
• wherein polarization dispersion of the object is obtained by measuring a delay time of the outgoing optical pulse passing through the object on the basis of intervals between peaks of the optical waveform of the multiplexed light.