Dual-wavelength Generation Research Articles

Widely tunable dual-wavelength optical short pulse generation in a self-seeding scheme

Two gain-switched Fabry–Pérot laser diodes have been used in a self-seeding scheme for widely tunable dual-wavelength optical short pulse generation. The wavelengths and their spacing can be tuned in a flexible manner by adjustment of the wavelength-selective elements that consist of a fiber Bragg grating and a tunable optical filter. The side-mode suppression ratio of the output pulses achieved is better than 26 dB over a wavelength-tuning area of approximately 30 nm.

Mutual pulse injection-seeding scheme by the use of two Fabry–Pérot laser diodes for tunable dual-wavelength optical short-pulse generation

Two Fabry–Pérot laser diodes, one being gain switched and the other dc biased, are used in a mutual pulse injection-seeding scheme for tunable dual-wavelength optical short-pulse generation. Wavelength selection and tuning are achieved by adjusting two fiber Bragg gratings and optical delay lines while a constant repetition frequency of 1.5053 GHz is maintained. An erbium-doped fiber amplifier is employed to enhance light intensity injected to the laser diode. The sidemode suppression ratio of the output pulses achieved is better than 25 dB over the wavelength-tuning range of 12.1 nm. The system is robust, flexible, and convenient for wavelength tuning.

Dual‐wavelength optical short‐pulse generation and wavelength switching using multiple‐optical‐paths

AbstractDual‐wavelength optical picosecond pulses are generated simultaneously by using a multiple‐optical‐path self‐seeding scheme. The external cavity of the Fabry–Perot (F–P) laser diode consists of three fiber Bragg gratings (FBGs) and a variable optical delay line. The wavelengths of the optical short pulses can be selected conveniently by adjusting the FBG and switched simply by adjusting the optical delay line. A side mode suppression ratio of better than 18 dB is achieved by using a 1:99 optical coupler to enhance the seeding power. The system is simple, easy to operate, and low cost. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 233–235, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10730

Single- and dual-wavelength pulse train generation in frequency-modulated Er–Yb lasers up to [formula omitted

In this paper we present recent results obtained on the generation of ultra-high repetition rate optical pulse trains at 1.5 μm in asynchronously frequency-modulated Er–Yb : glass lasers. Nearly transform-limited pulse trains at either single or dual carrier wavelength with repetition rates up to ∼20 GHz are generated by means of an external fiber Bragg grating. These pulse trains are of great potential interest for soliton-based optical transmission systems.

Three-terminal semiconductor laser for wave mixing

We suggest and analyze the concept of a semiconductor laser device that incorporates two basic ideas: (i) dual-wavelength generation of two optical fields on the interband transitions with independent control of each field in a three-terminal ``transistor'' scheme, and (ii) generation of infrared radiation in the 3\char21{}300 \ensuremath{\mu}m range due to nonlinear wave mixing of the above optical fields in the same laser cavity. Due to inversionless nature of the difference frequency generation and inherently low threshold current, the laser can be capable of continuous room-temperature operation in the mid/far-infrared and THz range.

Tunable dual-wavelength picosecond pulse generation by the use of two Fabry-Pe/spl acute/rot laser diodes in an external injection seeding scheme

An attractive alternative to generate tunable dual wavelength pulses by external injection seeding of a gain-switched Fabry-Pe/spl acute/rot laser diode (FP-LD) is demonstrated. The external injection-seeding branch consists of only a FP-LD, a 3-dB coupler and two fiber Bragg gratings (FBGs). The two wavelengths can be selected and their spacing can be tuned by adjusting two FBGs. The output sidemode-suppression- ratio is better than 17 dB over a 10 nm wavelength tuning range. The whole system is simple and of low cost.

Mid-infrared optical parametric generator with extra-wide (3–19-μm) tunability: applications for spectroscopy of two-dimensional electrons in quantum wells

Using a λ=2.8 µm pump makes it possible to take full advantage of notable nonlinear optical properties of the infrared crystals ZnGeP2, CdSe, and GaSe to achieve efficient mid-infrared frequency downconversion. Traveling-wave optical parametric generators with angular tuning were pumped by single 100-ps 2.8-µm Er,Cr:YSGG laser pulses. The continuous tuning range achieved was 3.9–10 µm (ZnGeP2), 3.57–4.3 and 8–13 µm (CdSe), and 3.3–19 µm (GaSe), with a quantum conversion efficiency of typically 10% and the lowest, to the author’s knowledge, threshold ever obtained for a traveling-wave optical parametric generator. A dual-wavelength optical parametric generator was used for nonlinear spectroscopy of intersubband transitions of conduction-band electrons, quantum confined in semiconductor quantum wells, as well as for the study of intersubband-based resonantly enhanced χ(2) in quantum wells.

5-GHz repetition-rate dual-wavelength pulse-train generation from an intracavity frequency-modulated Er-Yb:glass laser:?errata

In our recent Letter,(1) the affiliation of the authors was incorrect and should read as shown above. On p. 1549, in line 19 of the left-hand column the word "pulse" should be replaced with "trace." Finally, in Ref. 11 the name of the first author was misspelled. The correct reference should read as follows:

5-GHz repetition-rate dual-wavelength pulse-train generation from an intracavity frequency-modulated Er–Yb:glass laser

We report the experimental demonstration of nearly transform-limited dual-wavelength pulse trains at a 5-GHz repetition rate that were generated by spectral filtering of an intracavity 2.5-GHz frequency-modulated Er-Yb bulk-glass laser operating at the 1533-nm wavelength. Highly stable dual-wavelength pulse trains with approximately 165-GHz frequency separation, approximately 48-ps pulse duration, and approximately 1-mW average single-mode fiber-coupled power were obtained.

Visible dual-wavelength light generation in optical superlattice Er:LiNbO3 through upconversion and quasi-phase-matched frequency doubling

Optical superlattice Er:LiNbO3 was fabricated by inducing a periodic ferroelectric domain structure into the crystal during the growing process. Because of the combination of the nonlinear optical properties of LiNbO3 and the spectral properties of Er3+, the crystal can simultaneously emit the second harmonic light through quasi-phase matching and the green light through upconversion at room temperature. Pumped by infrared diode lasers, violet-and-green and blue-and-green light generation was demonstrated in two samples. The detailed absorption spectrum and emission spectrum of upconversion were measured. The possible physical mechanism was discussed.

Tunable dual-wavelength picosecond pulse generation using multiple-optical-path self-seeding approach

A simple system is developed to generate tunable dual-wavelength optical pulses by self-injection seeding of a laser diode. The wavelengths are selected by controlling two light paths incident on a single diffraction grating. The spectral separation has been tuned from 1.8 to 16.1 nm while maintaining an output side-mode-suppression-ratio (SMSR) over 21 dB. This multiple-optical-path self-seeding approach is simple and efficient, thus providing an attractive alternative to generate tunable multiwavelength pulses.

Dual-wavelength picosecond pulse generation usinga single grating and a Michelson interferometer in a self-injection seedingscheme

A single grating combined with a Michelson interferometer is used to generate dual-wavelength picosecond pulses by self-injection seeding of a laser diode. The wavelengths and their spacing can be readily tuned by adjusting the grating and the mirrors in the interferometer. The system is simple, robust, and is of low cost.

Dual-wavelength picosecond optical pulse generation using an actively mode-locked multichannel grating cavity laser

Picosecond pulse generation by active mode locking has been achieved simultaneously at two wavelengths using a multichannel grating cavity Laser. For a spectral channel separation of 2.2 nm, pulses of duration of 60 ps and with a spectral width of 11 GHz have been obtained. The pulse widths are limited by the spectral dispersion of the grating used.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>