We report the development of a fiber-coupled diode laser module with high spatial and spectral brightness. Four
arrays of diode laser bars are multiplexed using polarization and narrow-band wavelength combination. The module
achieves 500 W of output power from a 200 μm, 0.2 NA fiber. The output spectrum, composed of contributions
from more than 150 emitters, is narrowed using VBGs and has nearly 100% content within +/- 1.5 nm of 975 nm at
full power.
We report the development of a fiber-coupled diode laser module with high spatial and spectral brightness. Four arrays
of diode laser bars are multiplexed using polarization and narrow-band wavelength combination. The module achieves
500 W of output power from a 200 μm, 0.2 NA fiber. The output spectrum, composed of contributions from more than
150 emitters, is narrowed using VBGs and has nearly 100% content within +/- 1.5 nm of 975 nm at full power.
We describe the performance of diode laser bars mounted on conductive and water cooled platforms using low smile processes. Total smile of <1μm is readily achieved on both In and AuSn based platforms. Combined with environmentally robust lensing, these mounts form the basis of multiple, high-brightness products.
Free-space-coupled devices utilizing conductively-cooled bars delivering 100W from a 200μm, 0.22NA fiber at 976nm have been developed for pumping fiber lasers, as well as for materials processing. Additionally, line generators for graphics and materials processing applications have been produced. Starting from single bars mounted on water-cooled packages that do not require de-ionized or pH-controlled water, these line generators deliver over 80W of power into a line with an aspect ratio of 600:1, and have a BPP of <2mm-mrad in the direction orthogonal to the line.
Laser-based projection displays have long attracted interest because of the multiple advantages (expanded color gamut, high resolution, longer lifetime, etc.) expected from lasers as compared to lamps. However, most of these advantages have been largely negated by the significant cost, size, and cooling requirements associated with lasers, and their inability to produce red, green, and blue colors in the same platform. In this paper, we review a new, laser array
technology based of frequency-doubled, semiconductor, surface-emitting lasers. The key features of this technology, such as demonstrated multi-Watt output for rear-projection TVs, power levels scalable with the number of emitters, speckle suppression due to multi-emitter array, and a low-cost and compact design are discussed in detail.
Compact and efficient blue-green lasers have been receiving increasing interest in the last few years due to their applications in various industries: bio-instrumentation, reprographics, microscopy, etc. We report on the latest developments in frequency-doubled, compact blue-green lasers, based on Novalux extended-cavity surface emitting laser (NECSEL) technology. This discussion will touch upon using NECSEL technology to go beyond a 5-20 milliwatt cw laser design for instrumentation applications and obtain a compact design that is scalable to higher power levels in an array-based architecture. Such a blue-green laser array platform can address the needs of laser light sources in the projection display consumer electronics markets, particularly in rear-projection televisions.
We introduce a novel type of cw green laser source, the Protera 532, based on the intracavity frequency doubling of an extended-cavity, surface-emitting diode laser. The distinguishing characteristics of this platform are high compactness and efficiency in a stable, single-longitudinal mode with beam quality M2 < 1.2. The laser design is based on the previously reported NECSEL architecture used for 488nm lasers, and includes several novel features to accommodate different types of nonlinear optical materials. The infrared laser die wavelength is increased from 976nm to 1064nm without compromising performance or reliability. The intracavity frequency doubling to 532nm has been demonstrated with both bulk and periodically poled nonlinear materials, with single-ended cw power outputs of greater than 30 mW.
Laser sources emitting at 460nm have been developed through intracavity doubling of an extended cavity, surface emitting semiconductor laser. These lasers are compact, spectrally pure, efficient, and have a high quality beam. The basic design is similar to previously reported work[1] at 488nm using Novalux Extended Cavity Surface Emitting Laser (NECSEL) structures. The choice of nonlinear material was found to be critical, with periodically poled materials providing distinct benefits over bulk materials. Output powers exceeded 20mW. The reliability of the completed lasers was found to be excellent.
We describe the design, fabrication and performance of novel, electrically pumped, vertical compound cavity 976nm InGaAs lasers that emit at 488nm via intracavity second harmonic generation. The resulting light source is an ideal replacement for Ar-ion lasers used in a wide variety of bio-analytical instruments. We present characterization data for the laser to demonstrate its capabilities. Lastly, future directions for the technology are discussed, including a monolithic form and devices operating at 460 and 532nm.
We describe the properties of novel blue-green sources based on intracavity frequency doubling of the Novalux family of high-brightness infrared surface-emitting lasers. They are highly compact, efficient, reliable, stable and manufacturable, capable of emitting over 40-mW cw power at 488 nm and other custom wavelengths in the range 460-532 nm with single frequency and single-spatial mode.
We describe design and performance of novel, electrically pumped, vertical compound cavity semiconductor lasers emitting at 980 nm. The laser combines a vertical cavity semiconductor laser with a partially reflecting output coupler and an external cavity for mode control. The concept is scalable and has been demonstrated in monolithic low power (few miliwatts) devices all the way to high power extended cavity devices which generate over 950 mW CW multimode power and 0.5 W CW power in a TEM00 mode, the latter with 90% coupling efficiency into a single mode telecommunication fiber. The concept has been applied to the development of uncooled lasers, mounted in TO-56 cans, capable of producing 50 to 100 mW of fiber-coupled power. We have also demonstrated the extended cavity lasers at wavelengths of 920 nm and 1064 nm. We present reliability data for the chips used in the extended cavity lasers.
We describe a novel blue-green laser platform, based on the intracavity frequency doubling of Novalux Extended Cavity Surface Emitting Lasers. We have demonstrated 5 to 40mW of single-ended, 488nm, single-longitudinal mode emission with beam quality M2<1.2. The optical quality of these lasers matches that of gas lasers; their compactness and efficiency exceed ion, DPSS, and OPSL platforms. These unique properties are designed to serve diverse instrumentation markets such as bio-medical, semiconductor inspection, reprographics, imaging, etc., and to enable new applications. We also present data on the reliability of this novel laser platform and its extensions to different wavelengths (in particular, 460nm and 532nm) and to next-generation, highly compact, monolithic intracavity-doubled lasers.
We have developed novel electrically pumped, surface-emitting lasers emitting at 980 nm with an extended coupled cavity. The concept is scalable from monolithic low power (~10 mW) devices all the way to high power extended cavity lasers. The latter have demonstrated ~1 W cw multi-mode and 0.5 W cw in a TEM00 mode and a single frequency, with 90% coupling efficiency into a single-mode fiber. By inserting a nonlinear optical medium in the external cavity, efficient and compact frequency doubling has been achieved with CW output powers 5-40 mW demonstrated at 490 nm. The latter devices are especially noteworthy due to their very low noise (0.05% rms from dc-2 MHz), sub 10 mrad beam pointing stability combined with small size, low power consumption (<10 W) and high efficiency.
We have developed novel electrically pumped, surface-emitting lasers emitting at 980 nm with an extended coupled cavity. The concept is scalable from monolithic low power devices all the way to high power extended cavity lasers. The latter have demonstrated 1W cw multi-mode and 0.5 W cw in a TEM00 mode and a single frequency, with 90% coupling efficiency into a single-mode fiber. By inserting a nonlinear optical medium in the external cavity, efficient and compact frequency doubling has been achieved with CW output powers 5-40 mW demonstrated at 490 nm. The latter devices are especially noteworthy due to their very low noise, sub 10 μrad beam pointing stability combined with small size, low power consumption and high efficiency.
We describe design, fabrication and performance of novel, electrically pumped, vertical compound cavity InGaAs lasers emitting at 980 and 920 nm. The concept is scalable and has been demonstrated using monolithic low power (~10 mW) devices all the way to high power extended cavity devices which have demonstrated 1 W cw multi-mode and 0.5 W cw in a TEM00 mode and a single frequency, with 90% coupling efficiency into a single-mode fiber. We also describe uncooled vertical compound cavity lasers in TO-56 can packages which produce 50-100 mW of fiber coupled power. Finally, recent developments in intracavity frequency doubling are summarized.
In this paper we discuss our red, green, and blue (RGB) optical parametric oscillator (OPO) based laser projection display. The complete project display consists of two subsystems, the RGB-OPO laser head and the light modulation unit. The RGB lights from rack-mounted laser head are fibers coupled to the projection unit for independent placement. The light source consists of a diode-pumped pump laser and a LBO-based OPO. Based on our Nd:YLF gain module design, the pump laser is frequency doubled to serve as the pump source for the OPO. The unconverted pump power is recycled as the green light for projection. The singly resonant, non- critically phase-matched (NCPM) OPO has, to date, generated 13 W of 898-nm signal power and an estimated 9.3 W of intra- cavity idler power at 1256 nm. With approximately 76% of pump depletion, the power of the residual green light for projection is about 5.8 W. We have extra-cavity doubled the signal to produce approximately 3.5 W of 449-nm blue light and intra-cavity doubled the idler to produce approximately 6 W of 628-nm red light. The OPO-based RGB source generates about 4000 lumens of D65-balanced white light. The overall electrical power on a commercially available JVC's three- panel D-ILA (reflective LCD) projector with the arc-lamp removed and extensive modifications. The projector has a native resolution of 1365 x 1024 and the expected on screen lumens from our laser display is about 1200 lumens.
Electronic cinema projectors are being developed that use a digital micromirror device (DMDTM) to produce the image. Photera Technologies has developed a new architecture that produces truly digital imagery using discrete pulse trains of red, green, and blue light in combination with a DMDTM where in the number of pulses that are delivered to the screen during a given frame can be defined in a purely digital fashion. To achieve this, a pulsed RGB laser technology pioneered by Q-Peak is combined with a novel projection architecture that we refer to as Laser Digital CameraTM. This architecture provides imagery wherein, during the time interval of each frame, individual pixels on the screen receive between zero and 255 discrete pulses of each color; a circumstance which yields 24-bit color. Greater color depth, or increased frame rate is achievable by increasing the pulse rate of the laser. Additionally, in the context of multi-screen theaters, a similar architecture permits our synchronously pulsed RGB source to simultaneously power three screens in a color sequential manner; thereby providing an efficient use of photons, together with the simplifications which derive from using a single DMDTM chip in each projector.
In this paper we discuss our red, green, and blue (RGB) optical parametric oscillator (OPO) light source for projection display applications. Our source consists of a diode-pumped pump laser and a LBO-based OPO. Based on our Nd:YLF gain-module design, the pump laser is frequency doubled to serve as the pump source for the OPO. The unconverted pump power is recycled as the green light for projection. The singly resonant, non-critically phase- matched OPO has, to date, generated 13 W of 898-nm signal power and an estimated 9.3 W of intra-cavity idler power at 1256 nm. With approximately 76% of pump depletion, the power of the residual green light for projection is about 5.8 W. We have extra-cavity doubled the signal to produce approximately 3.5 W of 449-nm blue light and intra-cavity doubled the idler to produce approximately 6 W of 628-nm red light. The OPO-based RGB source generates about 4000 lumens of D65-balanced white light. The overall electrical power luminous efficiency (diodes only) is about 14.6 lumens/Watt.
A compact and efficient laser source is required as an enabling technology for laser projection displays. We discuss a scalable green-pumped, non-critically phase- matched LBO optical parametric oscillator (OPO) which simultaneously generates red and blue wavelengths that are ideal for display applications. Pumping the OPO with 9.7 W of 523 nm green light from a frequency-doubled, diode-pumped Nd:YLF oscillator/amplifier laser system has resulted in a measured 4.0 W of 896 nm signal power and an estimated idler power of 2.8 W. The signal was extra-cavity frequency doubled to produce 1.10 W of blue light at 448 nm. Intra- cavity frequency doubling of the idler produced 1.95 W of red light at 628 nm.
A compact and efficient laser source is required as an enabling technology for laser projection displays. We discuss a scalable green-pumped, non-critically phase-matched LBO optical parametric oscillator (OPO) which simultaneously generates red and blue wavelengths that are ideal for display applications. Pumping the OPO with 9.6 W of 523 nm green light from a frequency-doubled, diode-pumped Nd:YLF oscillator/amplifier laser system has resulted in a measured 3.6 W of 896 nm signal power and an estimated idler power of 2.6 W. The signal was extra-cavity frequency doubled to produce 0.65 W of blue light at 448 nm. Intra-cavity frequency doubling of the idler produced 1.66 W of red light at 628 nm.
We describe the operation of a cw phase-locked doubly resonant optical parametric oscillator that is suitable as a tunable optical source for the generation of terahertz radiation. A highly stable cw optical parametric oscillator has been constructed with a tuning range of several THz in the signal- idler difference frequency. By phase locking this difference frequency to a microwave source, either directly or with the use of a terahertz optical frequency comb generator, the parametric oscillator serves as a precisely tunable difference-frequency source. In one experiment, we phase locked the parametric oscillator at a signal-idler difference frequency of 665 GHz. In a second experiment, we measured a signal-idler difference frequency of 1.45 THz with the use of a diode-pumped YAG laser.
We report the experimental demonstration of tunable optical frequency division based on an efficient, one-step parametric downconversion process in a potassium titanyl phosphate (KTP) optical parametric oscillator (OPO). Our compact OPO generated two nearly degenerate subharmonic outputs that can be tuned over a 1.5 THz range in the signal-idler beat frequency by crystal angle tuning and cavity length scanning. We achieved continuous tuning of the beat frequency over a range of 0.5 GHz through the use of temperature and electro-optic tuning of the KTP crystal. A tunable optical frequency divider was realized by phase locking the signal- idler beat frequency to an external microwave frequency source, which yielded a beatnote linewidth at the sub-Hz level. The output frequencies of the phase-locked OPO were therefore precisely controlled by the tunable microwave source and the pump frequency. Characteristics of three different OPO cavity designs and their operations are discussed.
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.