Recently, W-class photonic-crystal surface-emitting lasers (PCSELs) with both a single spectrum and narrow spot beam pattern are reported. These highly coherent PCSEL properties cause a highly bright laser light that is useful for various applications. To improve the PCSEL output power, it is important to enlarge the emitting area to reduce the heat generation effect. However, multi-mode oscillation occurs in a broad emitting area because the difference in the threshold gain between the fundamental and higher modes becomes narrower as the emitting area is broadened. In this work, we fabricate PCSELs with double-hole lattice points that decrease the optical confinement to prevent multi-mode oscillation. The fabricated device, consisting of an AlGaAs/InGaAs material system designed to be oscillated at a wavelength of 940nm, has an emitting area of 300 × 300 μm2. In a square lattice photonic crystal whose lattice period equals the lasing wavelength embedded in PCSELs, the distance between the centers of the double hole is set to one quarter of the lasing wavelength to decrease in-plane coupling caused by interference. We confirm that this device is oscillated at the Γ point of band edge A in the photonic band structure. The peak power is more than 5 W under pulse operation at 10 A. The device has a narrow beam divergence of less than 1° and single lobe spectrum in spite of the broad emitting area, so these double-hole lattice points are an effective structure to improve the PCSEL output power.
The photoluminescence spectra of amorphous silicon rich silicon nitride films with various compositions were
investigated. Two main luminescence peaks were identified for all samples and blueshift of photoluminescence were
observed after annealing treatment. With the help of X-ray photoelectron spectroscopy and Fourier transform infrared
measurement, the chemical composition and bonding environment of samples, which were grown with different reactant
gases flow rates of plasma enhanced chemical vapor deposition, were analyzed. According to all these measurement
results, it is confirmed that the main luminescence centers are radiative recombination defects, such as silicon and nitride
dangling bonds. With proper deposition conditions, all these radiative recombination defects could be activated at the
same time, so that ultra-wide photoluminescence spectra with full width at half maximum of about 250nm ~ 300nm were
obtained in visible region.
High-quality (Q) factor photonic-crystal nanocavities are currently the focus of much interest because they can strongly
confine photons in a tiny space. Nanocavities with ultrahigh Q factors of up to 2,500,000 and modal volumes of a cubic
wavelength have been realized. If the Q factor could be dynamically controlled within the lifetime of a photon,
significant advances would be expected in areas of physics and engineering such as the slowing and/or stopping of light
and quantum-information processing. Here, we review the demonstration of dynamic control of the Q factor, by
constructing a system composed of a nanocavity, a waveguide with nonlinear optical response and a photonic-crystal
heterointerface mirror. The Q factor of the nanocavity was successfully changed from 3,800 to 22,000 within
picoseconds.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.