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Quality review method for optical components using a fast system performance characterization

Imported: 24 Feb '17 | Published: 24 Aug '04

Xudong Fan, James F. Brennan, III, Michael R. Matthews, Pranay G. Sinha, Jerome C. Porque

USPTO - Utility Patents

Abstract

A method for screening the quality of an optical component including the step of simulating the performance of the optical component. The step of simulating includes the step of measuring the optical phase of the optical component, wherein the step of measuring comprises indirectly measuring the optical phase of the optical component using a scanning laser having a scanning step size and a modulation frequency

m such that /

m

≦2. The light throughput R of the optical component is then measured. A transfer function H as a function of optical frequency is constructed where H()=R()exp[j()], and the performance is simulated using the measured value of the optical phase and the light throughput into the transfer function.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of how transfer function H() relates input signal X() and output signal Y().

FIG. 2 is a graph of a (a) group delay of a dispersion compensation grating measured with modulation phase shift method at fm=62.5 MHz; (b) group delay ripple measured at fm=62.5 MHz, fm=500 MHz, and fm=1150 MHz after subtraction of the gross group delay.

FIG. 3 is a graph of measured (upper curves) and calculated (bottom curves) (a) group delay ripple at fm=500 MHz, (b) group delay ripple at fm=1150 MHz.

FIG. 4 is a graph of total ripple amplitude function obtained from experimental measurement.

FIG. 5 is a graph of reflectivity (a) and phase (b) used to construct the transfer function, wherein

5(

c) is a magnified detail portion of FIG.

5(

a), and

5(

d) is a magnified detail portion of FIG.

5(

b).

FIG. 6 is a graph of 7-bit sequence used in simulation.

FIG. 7 is a graph of optical signal (top curves) of a 10 Gb/s “1-1-1” symbol (a) and a “1-1-1-1” symbol (b) measured at two different wavelengths after passing a DCFBG.

FIG.

8(

a) is a graph of Fourier components of a DCFBG group delay ripple interacting with the 10 Gb/s signal centered at one wavelength and

8(

b) is a graph of Fourier components of the group delay ripple of the same DCFBG interacting with the 10 Gb/s signal centered at another wavelength.

FIG. 9 is a graph of: (a) traces for bit “1” and bit “0”; (b) corresponding probability distribution of bit “1” and bit “0”.

FIG. 10 is a graph of noise-loaded 10 Gb/s NRZ test-bed system setup.

FIG.

11(

a) is a graph of comparison between simulated OSNR power penalty (bottom curves) and the test-bed measurement (upper curve) for a first sample and

11(

b) is a graph of comparison between simulated OSNR power penalty (bottom curves) and the test-bed measurement (upper curve) for a second sample.

FIG. 12 is a graph of normalized power versus wavelength of (a) modulation function spectra at various modulation frequencies measured using MPS method; (b) corresponding simulated modulation function spectra.

FIG. 13 is a graph of power penalty versus wavelength of a modulation transfer function that reflects the degradation in system performance.

FIG. 14 is a graph of normalized power versus modulation frequency of an experimental (a) and simulated (b) modulation transfer function at two wavelengths 1550.25 nm and 1551.85 nm showing different response for different Fourier components of input signal.

Claims

1. A method for screening the quality of an optical component, the method comprising the steps of:

/

m=2

H()=

R() exp[

j()], and

2. The method of claim 1, wherein the optical component is an optical Bragg grating having a bandwidth greater than 1 nanometer.

3. The method of claim 1, wherein

m<40 MHz.

4. The method of claim 1, wherein the optical component is an optical grating.

5. The method of claim 1, wherein the optical component is a dispersion compensation optical grating.

6. The method of claim 1, wherein the step of measuring comprises using an interferometer.

7. A method for simulating the performance of the optical component, the method comprising the steps of:

/

m=2

H()=

R() exp[

j()], and

8. The method of claim 7, wherein the optical component is an optical Bragg grating having a bandwidth greater than 1 nanometer.

9. The method of claim 7, wherein

m<40 MHz.

10. The method of claim 7, wherein the optical component is an optical grating.

11. The method of claim 7, wherein the optical component is a dispersion compensation optical grating.

12. The method of claim 7, wherein the step of measuring comprises using an interferometer.