Grating Cavity Laser Research Articles

Structural Dependence of Tuning Range and Mode Stability in Grating Cavity Laser With Beam Deflector

The dependence of tuning range and sidemode suppression ratio (SMSR) in Littrow-type grating cavity laser with beam deflector on structural parameters is investigated. The proposed tuning model gives a good agreement with the experimental results. It is confirmed that the device can have the maximum tuning range of about 13 nm with SMSR of 30 dB according to tradeoff relation between tuning range and SMSR. The dependence of mode stability in the device is also examined. It appears there is additional tradeoff between mode stability and output power on the structural parameters

Widely Tunable Grating Cavity Lasers

A widely tunable multi-channel grating cavity laser is proposed and experimentally demonstrated. The device is implemented in Littman configuration with an echelle grating based on Rowland circle construction and realized by monolithically integrating all elements in an InP substrate. Lasing wavelength is selected by turning on an amplifier and the appropriate channel element in the array, and it is tuned by controlling light deflection electrically. The 6-channel device exhibits a tuning range of about 50 nm with a side mode suppression ratio of more than 30 dB. This is accomplished by adjusting the applied current of the dispersive element and phase control section.

Widely tunable multichannel grating cavity laser

A widely tunable grating cavity laser based on the Rowland circle construction for a concave grating is proposed and demonstrated. The device is implemented by employing multichannel array structure in a Littman configuration and fabricated by integrating all elements in an InP substrate. Only one channel is turned on at a time, with coarse tuning realized by selecting the appropriate element in the channel array and fine tuning by controlling the beam deflection provided by dispersive element. An overall tuning range of 50 nm with a sidemode suppression ratio of more than 30 dB has been achieved for the six-channel device

Monolithically integrated multiwavelength grating cavity laser

A multiwavelength grating cavity laser is reported using a novel design for a multichannel light source based on an etched diffraction grating. Following the design, the compact eight-channel device capable of fine-tuning has been realized by monolithically integrating semiconductor optical amplifiers, various passive waveguides, and deeply etched grating, providing high butt-coupling efficiency, and low waveguide losses. As a result, the sidemode suppression ratio in excess of 45 dB over all channels was achieved.

Measurements of linewidth variations within external-cavity modes of a grating-cavity laser

Linewidth variations within an external-cavity mode of a grating-cavity laser were measured with high accuracy using the self-homodyne technique with a short delay line. To our knowledge, this is the first time that these variations have been accurately measured. In our laser, we observed the linewidth to change by a factor of five from 30 kHz to more than 150 kHz when the laser was tuned over a single external-cavity mode. A simple model based on a linear relationship between the chirp reduction factor and the frequency tuning of the laser is used to describe the results.

1 × 4 space switching and simultaneous all-opticalwavelength conversion at 2.488 Gbit/s using a single monolithically integrated multiwavelength laser

A novel InGaAs/InGaAsP/InP integrated multiwavelength grating cavity laser is presented, which has been used to demonstrate space switching and simultaneous all-optical wavelength conversion at bit rates of 2.488 Gbit/s. This has been achieved using a single monolithically integrated device without the need for post-filtering to separate the converted signal from the input.

Variable delay dual wavelength picosecond optical pulse generation using an actively mode-locked multichannel grating cavity laser

Two optical pulse trains are generated at different wavelengths with a programmable delay between them, using active mode-locking of a multichannel grating cavity laser. For a channel separation of 2.2 nm, pulses with a duration of 60 ps and with a spectral width of 11.6 GHz have been obtained at a repetition rate of 1.78 GHz. The pulse width and power are stable to within 6%, irrespective of delay for a relatively wide range of dc bias conditions.

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>

Multiple channel signal generation using multichannel grating cavity laser with crosstalk compensation

A multichannel grating cavity (MGC) laser has been used to generate WDM channels simultaneously using a novel crosstalk compensation scheme. With a channel spectral separation of 2.2nm in the 1.5μm wavelength range, crosstalk levels of better than 20dB have been achieved. Good agreement is obtained between theory and experiment.

A multichannel grating cavity laser for wavelength division multiplexing applications

A novel form of wavelength selectable diode laser source is proposed for wavelength division multiplexing (WDM) applications. The source may be used to operate at specific wavelengths across the complete gain spectrum of the laser diode material, but does not require any moving parts. Theoretical simulations indicate that the device can be expected to operate in a single longitudinal mode for channel separations on the order of 1 nm. The potential of using the device to generate parallel streams of WDM data is considered.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Multichannel grating cavity (MGC) laser transmitter for wavelength division multiplexing applications

A detailed experimental investigation of a wavelength switchable multichannel grating cavity (MGC) laser is reported with properties particularly suitable for applications in broadband wavelength division multiplexing systems. The source consists of a bar of laser ridges with one facet antireflection (AR) coated, a collimating lens and a diffraction grating. By changing the electrical bias to individual laser ridges, precise wavelength switching is achieved across the complete gain spectrum of the diode laser material. A detailed investigation of multiple simultaneous channel generation is reported and a method is outlined to overcome channel crosstalk. Good agreement between theory and experiment is reported.

Demonstration of a 1×2 multichannel grating cavity laser for wavelength division multiplexing (WDM) applications

A new form of diode laser source for wavelength-division multiplexing (WDM) applications is reported. The source has been designed to operate in systems requiring wavelength separations between channels of more than 1 nm and provides exact control of channel separation with low crosstalk. Simultaneous multiwavelength generation is also possible. >