Abstract: A self-seeded optical parametric amplifier (OPA) system includes a cavity mirror, a wavelength conversion unit, and a dichroic filter. The cavity mirror is configured to allow high transmission for an input laser beam and high reflection for a feedback beam. The wavelength conversion unit is configured to convert the input laser beam into a signal laser beam and an idler laser beam. The dichroic filter is configured to allow one of the signal laser beam and the idler laser beam to pass through the dichroic filter and reflect the other one onto a feedback path.

Abstract: A laser system and a laser outputting method are disclosed. The method comprises: providing a oscillator, wherein the oscillator comprises a pump light source, a cavity and a mode locked controller; utilizing the pump light source to emit a pump light into the cavity; outputting first laser pulses to the spectrum converter; utilizing a wavelength conversion chip of the spectrum converter to convert the first laser pulses to second laser pulses; utilizing at least one photo-detector to detect a power of the second laser pulses; controlling the mode locked controller to modulate a mode-locked status of the cavity when the power of the second laser pulses is lower than a threshold value.

Abstract: A compact optical system is provided. The system includes a first optical module, a first substrate, a second optical module, and a second substrate. The first optical module is utilized to modulate a laser beam. The first substrate supports the first optical module, and the first substrate defines a first optical via such that the laser beam can pass through the first substrate through the first optical via. The second optical module receives the laser beam from the first optical via for modulating the laser beam. The second substrate is disposed parallel to the first substrate and away from the first substrate with a first predetermined distance and utilized to support the second optical module. An ultrafast laser thereof is further provided.

Abstract: A compact optical system is provided. The system includes a first optical module, a first substrate, a second optical module, and a second substrate. The first optical module is utilized to modulate a laser beam. The first substrate supports the first optical module, and the first substrate defines a first optical via such that the laser beam can pass through the first substrate through the first optical via. The second optical module receives the laser beam from the first optical via for modulating the laser beam. The second substrate is disposed parallel to the first substrate and away from the first substrate with a first predetermined distance and utilized to support the second optical module. An ultrafast laser thereof is further provided.

Abstract: A light conversion module includes a coupler for combining two light beams to form a combined light beam, a nonlinear crystal arranged to receive the combined light beam and configured to include a plurality of poling regions for performing successive nonlinear frequency mixing processes, a first optical device configured to focus the combined light beam onto the nonlinear crystal, a first moving stage carrying the nonlinear crystal and moving the nonlinear crystal for an adjustment of a focus position of the combined light beam on the nonlinear crystal, and an optical detector configured for measuring a power level of the light beam from the nonlinear crystal for the adjustment of the focus position of the combined light beam on the nonlinear crystal.

Abstract: A light conversion module includes a coupler for combining two light beams to form a combined light beam, a nonlinear crystal arranged to receive the combined light beam and configured to include a plurality of poling regions for performing successive nonlinear frequency mixing processes, a first optical device configured to focus the combined light beam onto the nonlinear crystal, a first moving stage carrying the nonlinear crystal and moving the nonlinear crystal for an adjustment of a focus position of the combined light beam on the nonlinear crystal, and an optical detector configured for measuring a power level of the light beam from the nonlinear crystal for the adjustment of the focus position of the combined light beam on the nonlinear crystal.

Abstract: A wavelength converter includes a supporting substrate and a ferroelectric substrate, the ferroelectric substrate includes at least one waveguide facing the supporting substrate and at least one wavelength-filtering pattern positioned between the waveguide and the supporting substrate, the waveguide includes a plurality of inverted domains and non-inverted domains configured to convert an infrared light into a green light, and the infrared light emitted from the semiconductor laser enters the waveguide of the wavelength converter. For example, the wavelength-filtering pattern includes a Bragg grating.

Abstract: A wavelength converter includes a supporting substrate and a ferroelectric substrate, the ferroelectric substrate includes at least one waveguide facing the supporting substrate and at least one wavelength-filtering pattern positioned between the waveguide and the supporting substrate, the waveguide includes a plurality of inverted domains and non-inverted domains configured to convert an infrared light into a green light, and the infrared light emitted from the semiconductor laser enters the waveguide of the wavelength converter. For example, the wavelength-filtering pattern includes a Bragg grating.

Abstract: A wavelength converter structure comprises a supporting substrate, a ferroelectric substrate having at least one ridge waveguide including a plurality of periodic poled regions positioned on a first side of the ferroelectric substrate, and at least one controlling pattern positioned on a second side of the ferroelectric substrate. The ridge waveguide is joined to the supporting substrate via an adhesive, and the second side is opposite to the first side.

Abstract: A light-generating apparatus comprises a broadband pumping laser configured to emit a broadband pumping light having a bandwidth larger than 10 nanometers and a broadband wavelength-converting device. The broadband wavelength-converting device includes a domain-inverted structure configured to convert the broadband pumping light into at least one conversion light by using at least a sum frequency generation mechanism and at least one waveguide positioned in the domain-inverted structure, and the waveguide has an input end configured to receive the broadband pumping light and an output end configured to output the conversion light. Since the light-generating apparatus uses the broadband pumping laser and the broadband wavelength-converting device, it is temperature-insensitive and speckle-free.

Abstract: A periodically poled element comprises a ferroelectric substrate having a top surface, a bottom surface, a top electrode structure including at least one conductor positioned on the top surface, and a suppressing structure including at least one insulator positioned on the top surface and a gap separating the insulator from the conductor. The ferroelectric substrate has a predetermined polarization direction, the conductor is configured to form an inverted domain with an inverted polarization direction in the ferroelectric substrate as a predetermined voltage is applied during a poling process, and the suppressing structure is configured to suppress the spreading of the inverted domain during the poling process.

Abstract: A light source comprises a light-emitting module configured to emit a first beam and an array waveguide configured to convert the first beam into a second beam. The light-emitting module includes a plurality of light-emitting units configured to emit the first beam, and the light-emitting units are positioned in an array manner. The array waveguide includes a ferroelectric crystal with a first polarization direction, a plurality of inverted domains positioned in the ferroelectric crystal and a plurality of wavelength-converting waveguides positioned in the ferroelectric crystal. The inverted domains have a second polarization direction substantially opposite to the first polarization direction, the wavelength-converting waveguides cross the inverted domains substantially in a perpendicular manner, and the inverted domains are configured to convert the first beam from the light-emitting module into second beam as the first beams propagate through the wavelength-converting waveguides.

Abstract: A method for preparing a poled structure by using double-sided electrodes to perform a poling process first provides a ferroelectric substrate with a first polarization direction having a top surface and a bottom surface. Fabrication processes are then performed to form an electrode structure including a first electrode and a second electrode on the top surface and a third electrode in a portion of the bottom surface between the first electrode and the second electrode. Subsequently, a poling process is performed on the electrode structure to form a plurality of inverted domains having a second polarization direction in the ferroelectric substrate, and the second polarization direction is substantially opposite to the first polarization direction.

Abstract: A method for preparing a poled structure forms a ferroelectric substrate with a first polarization direction, wherein the ferroelectric substrate has a first surface and a second surface. An electrode-patterning process is then performed to form a first electrode structure on the first surface, and the first electrode structure includes a plurality of active blocks and a plurality of passive blocks, wherein at least one passive block is sandwiched between two active blocks. Subsequently, a poling process is performed including applying a predetermined voltage to the active blocks and floating the passive blocks such that a current such as a leakage current or a tunnel current is generated from the active blocks to the passive blocks to form a plurality of inverted domains with a second polarization direction in the ferroelectric substrate.

Abstract: A method for preparing a periodically poled structure according to this aspect of the present invention comprises the steps of providing a ferroelectric substrate and performing a poling process by applying a poling current to at least one portion of the ferroelectric substrate according to a current waveform. The current waveform include a major phase and a tailed phase accompanying the major phase; the major phase has at least one peak current (Ip) and terminates when the current drops substantially equal to Ip/e, and the charge delivered to the portion of the ferroelectric substrate during the major phase is larger than that delivered during the tailed phase. The nucleation phase is configured to generate nucleation sites in the portion of the ferroelectric substrate and the spreading phase is configured to increase the size of the nucleation sites.

Abstract: A method for preparing a poled structure comprises the steps of forming a ferroelectric substrate having a top surface and a bottom surface, performing a doping process to form at least one inhibition block in the ferroelectric substrate, forming an electrode structure including a first electrode and a second electrode on the top surface and a third electrode on the bottom surface and applying a predetermined voltage to the electrode structure to form a plurality of inverted domains outside of the inhibition block in the ferroelectric substrate. The ferroelectric substrate has a first polarization direction and a first crystal structure, the inhibition block has a second crystal structure different from the first crystal structure, and the inverted domains have a second polarization direction substantially opposite to the first polarization direction.

Abstract: A periodic poling structure comprises a ferroelectric substrate including a plurality of tunnels, a plurality of first domains positioned in the ferroelectric substrate between the tunnels and a plurality of second domains interleaved between the first domains in the ferroelectric substrate. Each first domain has a first polarization direction, and each second domain has a second polarization direction different from the first polarization direction. The tunnels are disposed on a top surface and on a bottom surface of the ferroelectric substrate in an equal interval manner or in a variant interval manner. Particularly, the second polarization direction is opposite to the first polarization direction. The periodic poling structure further comprises a plurality of conductive blocks covering the entire base surfaces of the tunnels, or separated from the sidewalls of the tunnels by insulation gaps such that the conductive blocks cover only a portion of the base surfaces of the tunnels.

Abstract: A poled structure comprises a ferroelectric substrate having a top surface and a bottom surface, at least one inhibition block positioned in the ferroelectric substrate, an electrode structure including a first electrode and a second electrode on the top surface and a third electrode in a portion of the bottom surface between the first electrode and the second electrode and a plurality of inverted domains positioned outside of the inhibition block in the ferroelectric substrate. The ferroelectric substrate has a first polarization direction and a first crystal structure, the inhibition block has a second crystal structure different from the first crystal structure, and the inverted domains has a second polarization direction substantially opposite to the first polarization direction.

Abstract: A method for preparing a periodically poled structure according to this aspect of the present invention comprises the steps of providing a ferroelectric substrate and performing a poling process by applying a poling current to at least one portion of the ferroelectric substrate according to a current waveform. The current waveform include a major phase and a tailed phase accompanying the major phase; the major phase has at least one peak current (Ip) and terminates when the current drops substantially equal to Ip/e, and the charge delivered to the portion of the ferroelectric substrate during the major phase is larger than that delivered during the tailed phase. The nucleation phase is configured to generate nucleation sites in the portion of the ferroelectric substrate and the spreading phase is configured to increase the size of the nucleation sites.

Abstract: A method for preparing a periodically poled structure comprises the steps of providing a ferroelectric substrate having an upper surface and a bottom surface, forming an upper electrode including at least one first block and at least one second block on the upper surface, forming a bottom electrode including at least one third block and at least one fourth block on the bottom surface and performing a plurality of poling processes to form at least one first domain and at least one second domain in the ferroelectric substrate, wherein the first domain is formed between the first block and the third block, and the second domain is formed between the second block and the fourth block.