Thermal Compensation for Burst-Mode Laser Wavelength Drift
AssigneeFuturewei Technologies, Inc.
InventorsXuejin Yan, Jianmin Gong, Hongbing Lei, Jianhe Gao
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Abstract
An apparatus comprising a burst-mode laser comprising an active layer and configured to emit an optical signal during a burst period, wherein a temperature change of the burst-mode laser causes the optical signal to shift in wavelength, and a heater thermally coupled to the active layer and configured to reduce a wavelength shift of the optical signal during the burst period by applying heat to the active layer based on timing of the burst period.
Claims21
An apparatus comprising:
- a burst-mode laser comprising an active layer and configured to emit an optical signal during a burst period, wherein a temperature change of the burst-mode laser causes a wavelength shift of the optical signal;
- and
- a heater thermally coupled to the active layer and configured to:
- receive an electric current for generating heat, wherein the electric current is at a first level during a first period before a start of the burst period, at a second level during a second period after the start, and at zero during a third period after the second period, and wherein the first level is greater than the second level;
- and
- apply the heat to the active layer before the start and based on timing of the burst period in order to substantially stabilize a temperature of the burst-mode laser during the burst period and to reduce the wavelength shift during the burst period.
An apparatus comprising:
- a burst-mode laser comprising an active layer and configured to emit an optical signal during a burst period, wherein a temperature change of the burst-mode laser causes a wavelength shift of the optical signal;
- and
- a heater thermally coupled to the active layer and configured to:
- receive an electric current for generating heat, wherein the electric current reaches at least three levels during the burst period, reaches a first level no later than a start of the burst period, and then decreases from the first level;
- and
- apply the heat to the active layer at the start and based on timing of the burst period in order to reduce the wavelength shift during the burst period.
A method for temperature compensation during operation of a burst-mode laser that is thermally coupled to a heater, the method comprising:
- receiving a burst enable signal indicating a start of a burst period;
- emitting an optical signal with at least one wavelength during the burst period;
- supplying an electric current to the heater, wherein the electric current reaches a first level no later than the start and then decreases from the first level thereafter;
- applying, using the heater, a heat to the burst-mode laser based on the burst enable signal;
- and
- substantially maintaining, based on the applying, a temperature of the burst-mode laser throughout an emission of the optical signal in order to reduce a wavelength shift of the optical signal.
A laser system comprising:
- a burst-mode laser comprising a metallic layer configured to serve as an electrode pad for the burst-mode laser;
- and
- an electric heater situated atop the burst-mode laser and comprising:
- a first titanium (Ti) layer atop the metallic layer;
- a silicon dioxide (SiO2) layer atop the first Ti layer, comprising a first thickness no more than 300 nanometers (nm), and configured to allow efficient heat transfer from the electric heater to the burst-mode laser;
- a second Ti layer atop the SiO2 layer;
- and
- a platinum (Pt) layer atop the second Ti layer,
- wherein the second Ti layer and the Pt layer are configured to serve as a heating pad for the electric heater, and
- wherein the SiO2 layer is further configured to block current injection from the heating pad to the electrode pad.
Dependencies are inferred from the claim text.