Prof. Robert L. Byer Profile

Prof. Robert L. Byer

Director of Ginzton Lab at Stanford Univ

SPIE Involvement:

Conference Program Committee | Author

Publications (34)

PROCEEDINGS ARTICLE | April 21, 2017

Efficient cascaded half-harmonic generation of mid-IR frequency combs (Conference Presentation)

Proc. SPIE. 10088, Nonlinear Frequency Generation and Conversion: Materials and Devices XVI

KEYWORDS: Mid-IR, Optical parametric oscillators, Femtosecond phenomena, Frequency combs, Nonlinear dynamics, Harmonic generation, Frequency conversion, Sum-frequency generation, Femtosecond frequency combs, Current controlled current source

Read Abstract

PROCEEDINGS ARTICLE | February 15, 2012

Broadband mid-IR subharmonic OPOs for molecular spectroscopy

Proc. SPIE. 8240, Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XI

KEYWORDS: Mid-IR, Mirrors, Optical parametric oscillators, Resonators, Sensors, Dispersion, Crystals, Frequency combs, Laser crystals, Dielectric mirrors

Read Abstract

We generate broadband mid-infrared frequency combs via degenerate optical parametric oscillation in a subharmonic OPO. This technique efficiently transfers the desirable properties of shorter wavelength mode-locked sources to the mid- IR. Our OPO resonator is a 3m or 4m ring cavity composed of one pair of concave mirrors with R=50mm and four flat mirrors, all but one of which are gold coated with > 99% reflection. A single dielectric mirror is used to introduce the pump (2.05 micron from IMRA America, 75 MHz, 80 fs, 600mW or 1.55 micron from Menlo Systems C-fiber, 100 MHz, 70 fs, 350 mW or 1.56 micron from Toptica Photonics FemtoFiber Pro, 80 MHz, 85 fs, 380 mW). The dielectric mirror is transmissive for the pump and reflective in a 2.5- 4 micron or 3- 6 micron (for 2 micron pump) range. Broadband parametric gain around the 3.1-micron subharmonic is provided by short (0.2-0.5mm) periodically poled lithium niobate (MgO:PPLN) at Brewster angle. Crystals were cut from Crystal Technology Inc. material having QPM period of 34.8 microns for type 0 (e=e+e) phase matching at t=32 deg. C. With the 2-micron pump, orientation patterned gallium arsenide from BAE systems is used as the non-linear material In both systems, the enormous acceptance bandwidth at degeneracy, typical for OPOs with type 0 (or type I) phase-matching, gives broad bandwidth and makes temperature tuning insignificant. Broadband oscillation is achieved when signal/idler are brought into degenerate resonance by fine-tuning the cavity length with a mirror on a piezo stage. Using an 8% reflective pellicle, we outcouple a frequency comb of more than 1000nm bandwidth, centered around 3.1 microns from the Er/PPLN system. A 1mm or 2.5mm thick ZnSe plate at Brewster angle provides 2nd-order group velocity dispersion compensation, improving the OPO bandwidth. The OPO threshold was measured to be < 30mW. When locked, the OPO outputs 60 mW of average power centered at 3.1 microns. With the Tm/OP-GaAs system we achieve octave-spanning output from 3- 6 micron using a mix of YAG and CaF for dispersion compensation and output powers over 30 mW.

PROCEEDINGS ARTICLE | February 22, 2011

Mid-IR spectral comb with broad instantaneous bandwidth using subharmonic OPO

Proc. SPIE. 7917, Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications X

KEYWORDS: Mid-IR, Mirrors, Optical parametric oscillators, Resonators, Sensors, Dispersion, Crystals, Reflectivity, Frequency combs, Dielectric mirrors

Read Abstract

PROCEEDINGS ARTICLE | February 24, 2010

Compact couplers for overmoded three-dimensional photonic crystal waveguides

Proc. SPIE. 7609, Photonic and Phononic Crystal Materials and Devices X

KEYWORDS: Waveguides, Particles, Dielectrics, Photonic crystals, Free space, Wave propagation, Particle accelerators, Particle beams, Charged particle optics, Fusion energy

Read Abstract

PROCEEDINGS ARTICLE | February 24, 2009

Self-phase-locked divide-by-2 optical parametric oscillator as a broadband frequency comb source

Proc. SPIE. 7197, Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications VIII

KEYWORDS: Mid-IR, Fringe analysis, Second-harmonic generation, Continuous wave operation, Optical parametric oscillators, Mode locking, Photons, Crystals, Frequency combs, Nonlinear crystals

Read Abstract

PROCEEDINGS ARTICLE | February 25, 2008

Measurement of high-photodarkening resistance in phosphate fiber doped with 12% Yb₂O₃

Proc. SPIE. 6873, Fiber Lasers V: Technology, Systems, and Applications

KEYWORDS: Optical fibers, Silica, Nanoparticles, Glasses, Ions, Resistance, Fiber lasers, Ytterbium, Color centers, Absorption

Read Abstract

PROCEEDINGS ARTICLE | February 14, 2008

Design of transverse Nd doping profiles in transparent YAG ceramics for edge-pumped laser geometries

Proc. SPIE. 6871, Solid State Lasers XVII: Technology and Devices

KEYWORDS: Refractive index, Genetic algorithms, Ceramics, Nd:YAG lasers, Doping, Laser beam propagation, Wave propagation, YAG lasers, Neodymium, Absorption

Read Abstract

PROCEEDINGS ARTICLE | February 20, 2007

Measurement of the stimulated Brillouin scattering gain coefficient of a phosphate fiber

Proc. SPIE. 6469, Optical Components and Materials IV

KEYWORDS: Oxides, Optical fibers, Silica, Scattering, Signal attenuation, Glasses, Fiber lasers, Ytterbium, Neodymium, Acoustics

Read Abstract

PROCEEDINGS ARTICLE | February 8, 2007

2.6-watt average-power mode-locked ceramic Nd:YAG laser

Proc. SPIE. 6469, Optical Components and Materials IV

KEYWORDS: Second-harmonic generation, Modulation, Output couplers, Mode locking, Crystals, Ceramics, Nd:YAG lasers, Semiconductor lasers, Picosecond phenomena, Pulsed laser operation

Read Abstract

PROCEEDINGS ARTICLE | October 17, 2003

Thermal and fluid processes of a thin melt zone during femtosecond laser ablation of glass

Proc. SPIE. 4977, Photon Processing in Microelectronics and Photonics II

KEYWORDS: Microfluidics, Femtosecond phenomena, Borosilicate glass, Glasses, Laser energy, Laser processing, Laser ablation, Ultrafast lasers, Pulsed laser operation, Plasma

Read Abstract

PROCEEDINGS ARTICLE | March 3, 2003

Disturbance reduction system: testing technology for precision formation control

Proc. SPIE. 4860, High-Contrast Imaging for Exo-Planet Detection

KEYWORDS: Microfluidics, Aerospace engineering, Interferometers, Sensors, Electrodes, Magnetism, Control systems, Space operations, Control systems design, Prototyping

Read Abstract

PROCEEDINGS ARTICLE | February 26, 2003

Disturbance reduction system: testing technology for drag-free operation

Proc. SPIE. 4856, Gravitational-Wave Detection

KEYWORDS: Electronics, Interferometers, Sensors, Electrodes, Ultraviolet radiation, Magnetism, Control systems, Capacitance, Sensing systems, Space operations

Read Abstract

PROCEEDINGS ARTICLE | February 26, 2003

Test mass materials for a new generation of gravitational wave detectors

Proc. SPIE. 4856, Gravitational-Wave Detection

KEYWORDS: Mirrors, Silica, Interferometers, Sensors, Silicon, Sapphire, Radiation effects, Astatine, Temperature metrology, Absorption

Read Abstract

PROCEEDINGS ARTICLE | June 18, 2002

Femtosecond laser machining of fluidic microchannels for miniaturized bioanalytical systems

Proc. SPIE. 4637, Photon Processing in Microelectronics and Photonics

KEYWORDS: Ultrafast phenomena, Microfluidics, Femtosecond phenomena, Borosilicate glass, Glasses, Laser ablation, Objectives, Laser damage threshold, Pulsed laser operation, Laser systems engineering

Read Abstract

PROCEEDINGS ARTICLE | February 1, 2002

Deformable mirrors for high-power lasers

Proc. SPIE. 4493, High-Resolution Wavefront Control: Methods, Devices, and Applications III

KEYWORDS: Mirrors, High power lasers, Dielectrics, Silicon, Coating, Wavefront sensors, Adaptive optics, Deformable mirrors, Distortion, Semiconducting wafers

Read Abstract

PROCEEDINGS ARTICLE | February 1, 2002

Deformable mirror development at Stanford University

Proc. SPIE. 4493, High-Resolution Wavefront Control: Methods, Devices, and Applications III

KEYWORDS: Actuators, LIGO, Mirrors, Interferometers, Silicon, Wavefronts, Adaptive optics, Deformable mirrors, Semiconducting wafers, Surface micromachining

Read Abstract

PROCEEDINGS ARTICLE | November 22, 2000

Silicon deformable mirrors and CMOS-based wavefront sensors

Proc. SPIE. 4124, High-Resolution Wavefront Control: Methods, Devices, and Applications II

KEYWORDS: Actuators, Mirrors, Imaging systems, Silicon, Wavefront sensors, Wavefronts, Adaptive optics, Deformable mirrors, Charge-coupled devices, Semiconducting wafers

Read Abstract

PROCEEDINGS ARTICLE | June 14, 2000

Micro- and nanoscale domain engineering in lithium niobate and lithium tantalate

Proc. SPIE. 3992, Smart Structures and Materials 2000: Active Materials: Behavior and Mechanics

KEYWORDS: Lithium niobate, Lithium, Optical lithography, Switching, Visualization, Etching, Electrodes, Dielectrics, Semiconducting wafers, Nanodomains

Read Abstract

PROCEEDINGS ARTICLE | May 26, 1999

Domain patterning in lithium niobate using spontaneous backswitching

Proc. SPIE. 3610, Laser Material Crystal Growth and Nonlinear Materials and Devices

KEYWORDS: Visible radiation, Ferroelectric materials, Lithium niobate, Second-harmonic generation, Optical lithography, Spatial frequencies, Electrodes, Ultraviolet radiation, Nonlinear optics, Semiconducting wafers

Read Abstract

PROCEEDINGS ARTICLE | May 4, 1999

CW high-power conduction-cooled edge-pumped slab laser

Proc. SPIE. 3613, Solid State Lasers VIII

KEYWORDS: Continuous wave operation, Lasers, High power lasers, Interfaces, Laser development, Nd:YAG lasers, Semiconductor lasers, Diodes, Optical pumping, Absorption

Read Abstract

PROCEEDINGS ARTICLE | September 11, 1998

Micromachined silicon deformable mirror

Proc. SPIE. 3353, Adaptive Optical System Technologies

KEYWORDS: Actuators, Mirrors, Etching, Electrodes, Silicon, Reflectivity, Wavefront sensors, Deformable mirrors, Semiconducting wafers, Surface finishing

Read Abstract

PROCEEDINGS ARTICLE | May 2, 1997

Modeling of efficient mode-matching and thermal-lensing effect on a laser-beam coupling into a mode-cleaner cavity

Proc. SPIE. 2989, Modeling and Simulation of Higher-Power Laser Systems IV

KEYWORDS: Mirrors, Silica, Polarization, Coating, Distortion, Sapphire, Thermal effects, Optical resonators, Thermal modeling, Absorption

Read Abstract

PROCEEDINGS ARTICLE | May 10, 1996

Progress in quasi-phase-matched optical parametric oscillators using periodically poled LiNbO3

Proc. SPIE. 2700, Nonlinear Frequency Generation and Conversion

KEYWORDS: Continuous wave operation, Optical parametric oscillators, Crystals, Nd:YAG lasers, Laser damage threshold, Laser crystals, Q switched lasers, Nonlinear crystals, Semiconducting wafers

Read Abstract

PROCEEDINGS ARTICLE | May 10, 1996

Visible quasi-phase-matched harmonic generation by electric-field-poled lithium niobate

Proc. SPIE. 2700, Nonlinear Frequency Generation and Conversion

KEYWORDS: Visible radiation, Lithium niobate, Lithium, Optical lithography, Electrodes, Crystals, Manufacturing, Semiconductor lasers, Laser crystals, Harmonic generation

Read Abstract

PROCEEDINGS ARTICLE | May 8, 1996

Design for a GeV/m laser-driven electron accelerator

Proc. SPIE. 2701, Generation, Amplification, and Measurement of Ultrashort Laser Pulses III

KEYWORDS: Optical components, Prisms, Laser induced damage, Copper, Dielectrics, Laser damage threshold, Zirconium, Laser optics, Pulsed laser operation, Phase shifts

Read Abstract

PROCEEDINGS ARTICLE | April 10, 1995

40 W cw TEM00 mode diode-laser-pumped Nd:YAG zigzag miniature-slab laser

Proc. SPIE. 2379, Solid State Lasers and Nonlinear Crystals

KEYWORDS: Mirrors, Continuous wave operation, Resonators, Lasers, Birefringence, Coating, Laser development, Nd:YAG lasers, Semiconductor lasers, Diodes

Read Abstract

PROCEEDINGS ARTICLE | April 10, 1995

Quasi-phasematched optical parametric oscillators using bulk periodically poled LiNbO3

Proc. SPIE. 2379, Solid State Lasers and Nonlinear Crystals

KEYWORDS: Lithography, Continuous wave operation, Optical parametric oscillators, Electrodes, Metals, Crystals, Nd:YAG lasers, Semiconductor lasers, Photoresist materials, Laser damage threshold

Read Abstract

PROCEEDINGS ARTICLE | June 2, 1994

Investigations of diffusion-bonded stacked GaAs for infrared quasi-phase-matched parametric oscillation

Proc. SPIE. 2145, Nonlinear Optics for High-Speed Electronics and Optical Frequency Conversion

KEYWORDS: Second-harmonic generation, Optical parametric oscillators, Crystals, Gallium arsenide, Diffusion, Infrared radiation, Nonlinear crystals, Semiconducting wafers, Silver selenogallate, Absorption

Read Abstract

PROCEEDINGS ARTICLE | June 16, 1993

Design considerations for a 50-W cw, fundamental mode, diode-pumped solid state laser

Proc. SPIE. 1865, Diode Pumping of Average-Power Solid State Lasers

KEYWORDS: Mirrors, Continuous wave operation, Resonators, Birefringence, Laser development, Nd:YAG lasers, Reflectivity, Solid state lasers, Semiconductor lasers, Diode pumped solid state lasers

Read Abstract

PROCEEDINGS ARTICLE | April 30, 1993

Frequency-stability measurements of two nonplanar ring oscillators independently stabilized to two Fabry-Perot interferometers

Proc. SPIE. 1837, Frequency-Stabilized Lasers and Their Applications

KEYWORDS: Mirrors, Oscillators, Fabry–Perot interferometry, Phase modulation, Nd:YAG lasers, Control systems, Laser stabilization, Servomechanisms, Feedback control, Temperature metrology

Read Abstract

PROCEEDINGS ARTICLE | November 19, 1992

Optical generation of frequency stable mm-wave radiation using diode laser pumped Nd:YAG lasers

Proc. SPIE. 1839, Solid State Lasers and New Laser Materials

KEYWORDS: Photodetectors, Interferometers, Nd:YAG lasers, Semiconductor lasers, Diodes, YAG lasers, Laser optics

Read Abstract

PROCEEDINGS ARTICLE | December 1, 1991

Measurement of nonlinear optical coefficients by phase-matched harmonic generation

Proc. SPIE. 1561, Inorganic Crystals for Optics, Electro-Optics, and Frequency Conversion

KEYWORDS: Second-harmonic generation, Crystals, Optical testing, Nonlinear optics, Phase matching, Harmonic generation, Frequency conversion, Nonlinear crystals, Crystal optics, Silver selenogallate

Read Abstract

PROCEEDINGS ARTICLE | August 1, 1990

Nd:glass slab laser for x-ray lithography

Proc. SPIE. 1277, High-Power Solid State Lasers and Applications

KEYWORDS: Lithography, Mode locking, X-rays, Plasmas, Laser resonators, Photomasks, Neodymium glass lasers, Q switched lasers, X-ray detectors, X-ray lithography

Read Abstract

A Nd:Glass laser has been used to generate laser produced plasmas (LLP). The plasma emission in the keV range useful for X-ray lithography has been measured. Lithography with sub-micron linewidths has been demonstrated with a thin absorbing mask. The Nd:Glass slab laser is operated in a Q-switched one-dimensional unstable resonator. The resulting beam quality is a few times diffraction limited and is focused to an area less than the lO cm2 in our vacuum chamber. We have operated at 5 J up to 4 Hz repetition rate without any degradation of the laser output. Injection mode locking of the Nd:Glass laser with 0.7 ns pulses increases the intensity of the Q-switched laser output by about a factor of 10 and allows us to achieve a total integrated pulse length of less than 10 ns. Optical damage limits the laser intensity. The damage threshold for injection mode locked pulses focused into a Nd:Glass slab outside the laser cavity is about 20 J/cm2. However, we have observed another damage mechanism at lower intensities in Nd:Glass slabs in use in the laser head. Brown discoloration occurs in filaments along the laser beam path and we believe solarization with the help of self-focusing and the ultra- violet flashlamp radiation may be occuring. We are still investigating this phenomenon but at present it is limiting the laser output to only 2 J per pulse. The focused laser intensity is 2.1013 W/cm2 on a solid copper target in our vacuum chamber. The plasma emission in the keV X-ray range has been measured through a variety of thin film X-ray filters with a Hamamatsu micro-channel plate detector. Using the published values for the detector quantum efficiency, the micro-channel plate gain, and the filter's transmission spectra, we estimate that the conversion efficiency in the plasma from laser radiation to soft X-rays of energy greater than 0.5 keV is around 2%. We have performed single-level demonstration exposures of PNMA resist through a 10 im thick aluminised Kapton debris shield and a 4 im thick Boron Nitride X-ray mask supplied by Piero Pianetta the the Stanford Synchroton Research Laboratory. The 1.0 pm linewidth gold absorber patterns on the mask are accurately reproduced in the resist. The PMMA resist exposure rate at a 5 cm working distance from the plasma has been measured as 0.2 micron per lO J of total laser energy so we obtain a single layer exposure in about 30 minutes. The potential for improvement is enormous. The X-ray signal measured through the mask increases exponentially with the laser energy on target so increasing the focused intensity will reduce exposure rates dramatically. Available improvements in higher average power lasers and sensitised resists both offer an order of magnitude improvement over this system . These results indicate excellent potential for commercial LPP X-ray lithography.

PROCEEDINGS ARTICLE | April 1, 1990

Active frequency stabilization of diode-laser-pumped nonplanar ring oscillators

Proc. SPIE. 1223, Solid State Lasers

KEYWORDS: Optical amplifiers, Oscillators, Interferometers, Sensors, Nd:YAG lasers, Solid state lasers, Semiconductor lasers, Heterodyning, Laser stabilization, Servomechanisms

Read Abstract